Anna Sun, a talented violinist, is on the cusp of a career breakthrough – but she is struggling under the pressure. She no longer can play with the ease she once had. Then her long-time boyfriend announces that he wants them to have “an open relationship” and her therapist wants her to listen to her own needs, so Anna hooks up with Quan, determined to treat it as a one night stand. But their first date is a bit of a disaster, and so is the second one. But outside of dating, their relationship deepens, because Quan is the only person in her life to take her as she is and understand her. But when a personal tragedy strikes, they will both have to fight for their love.
“The Heart Principle” is the newest book by Helen Hoang and my favourite of hers so far. From the beginning I thought that the characters were so compelling and shown at their most vulnerable in such a sensitive way, that I felt connected with them and my heart could not stop aching. Both Anna and Quan have their own insecurities, and their love for each other was described by the author with extra care that it took this book to the whole new level. Helen Hoang did not shy away from writing about difficult subjects in her previous book, and this time she also approaches the themes of difficult health diagnosis, depression, burnout, grief, vulnerability, and responsibility towards one’s family in a delicate manner that also describes their complexities. To me, Anna’s struggles with her family’s lack of acceptance of her autism and her ill-fitting role as a dutiful daughter and sister, felt particularly raw. This is not your standard fluffy romance (although the author writes steamy sex scenes!), this is a story of a relationship that was won in a hard way, personal struggle, growth and being your true self.
The author also left a personal note to the reader, which explains partially the long wait and her personal take on the subjects described in the book. I am really grateful that Helen Hoang wrote this book. It just grabbed my heart from the start and resonated with me on so many levels.

I was kindly given an arc of this to read in NetGalley - thank you so much. This book was so highly anticipated for me, and boy did it live up to my expectations! I loved everything about this book and I wish I could read it again for the first time. I'll definitely be recommending it to everyone

There’s something special about Helen Hoang’s writing and storytelling. I’m immediately invested with the characters and ready to go on the journey with them. I’ve felt that with the two previous books and I felt that too with The Heart Principle. Unlike the previous two this one is written in first person POV and I didn’t expect that but when I read the author’s note after I finished I now understand why.

Anna was a character I somewhat could relate to and other times not all. At times I struggled with her but I also knew why that was. Her portrayal was flawlessly done and in particular her growth was truly amazing and so inspiring.
Quan was such a wonderful character. I couldn’t wait for his story after meeting him in book 1 and 2. He lived up to my expectations and so much more. Such a kindhearted and strong soul who listened to Anna. He had some struggles too and together he and Anna just made each other blossom as the story evolved.
I would have liked more romance as I think it took a backseat to Anna and her family struggles. Still I very much enjoyed The Heart Principle. Another strong and life affirming book from Hoang.

4 Keep Fighting Stars

Overall I absolutely loved this.
Helen Hoang truly has a way with words and dealing with mental health and other difficult topics.
I’m so happy that Quan got his own book! It was everything I needed it to be and more.
Would’ve been five star but I felt the pacing was slightly off toward the last 10% of the book. Everything wrapped up REALLY quickly and it was a bit unnerving.
Also found it odd that while Stella is mentioned frequently, and Khai does feature in this book, Esme isn’t mentioned at all, even in passing.
Not a bad thing necessarily, but after numerous mentions of Stella I was confused for Esme to not be mentioned and found myself wondering where she was.

I LOVED THIS BOOK! Honestly, how does Helen does it?! She has officially become one of my favourite romance writers. I absolutely love her books, her writing and her characters.

I had high expectations for this book, and let me tell you, Helen did not disappoint AT ALL!

This book is so much more than just a romance story. It’s deep, raw, and honest. The characters are real, human, natural, and flawed. It’s about fighting, keep going, and love, not only romantic but also about self-love and love for life. And it moved me deeply.

I love Helen’s writing so much. She always mingles real issues with lighthearted romance, but certainly, never meaningless. On the contrary, it has so much weight and significance, and she writes it in such a magnificent way that it doesn’t feel like a heavy book. Although, in this book, the romance is not as lighthearted and as the main issue as in the previous books, it’s still heartfelt and marvellous.


As always, I love the Autistic Spectrum representation in this book. I love ASD rep in any book really. However, this one was a tad different. I could tell there was a lot of heart in this book before even reading the Author’s note. It’s clear. And you can feel that. And that makes it even more special.

I was dying to read Quan’s story. I love him since TKQ, and this book made me love him even more. He’s such a perfect, unique man. So considerate, loving, caring, passionate, dedicated, and I could go on. And Anna, I love her. Her pain and struggles were so honest and real. I love how passionate and devoted she is. It’s true, sometimes she exasperated me a little, but mostly I just wanted to hug her and give her all my support.
And I just love how they are together. They’re just perfect for each other, and I wish there was more of them. Hopefully, we get to see some glimpses in the upcoming books.

Plus, I love My Octopus Teacher! and this book talks about it and I was so happy. If you haven’t watched that docu, please do yourself a favour and do it!

The only two things that I wished were different is that there were more scenes with Quan’s family. Or at least more with Michael and Khai. And that the issues could have been solved a little bit better.

If you like meaningful romance books, this is a must-read.

A absolute treat, the best from Helen yet. Her characters here are fully shaped, it’s a refreshing take on romance, and mostly importantly consent, where it models pretty well how open communication can enhance a love life. And though there was a small thing I would change at the end, Helen writes with her whole self here and you can tell, and if that’s the story she know then how can it be changed.

After falling absolute head over heels in love with The Kiss Quotient for the outstandingly positive portrayal of an autistic MC in a romance novel, I couldn’t get my hands on The Heart Principle fast enough.

A word of caution before going further: the story contains reference to past cancer and recovery, there’s an autism diagnosis, a family member’s stroke and subsequent care/palliative care, and there’s anxiety surrounding it all. Please take care if you may not presently be comfortable with this content.

So, it’s fair to say, this certainly delivered more than a fluffy smutty romance. It’s complex, emotional and thought provoking. Yet there were also moments where I was smiling ear to ear, feeling giddy and so joyful.

I looooooved Quan and Anna’s build, from tentative love interests to friends to lovers. I also loved their dating app interaction - I wish I could find my Quan to chat about lame but awesome octopus movies with!! They go from strength to strength, facing their insecurities together, finding solace in the other they haven’t found or felt comfortable sharing with anyone else, and it was just so tender.

I also loved how present Michael was (so you should definitely read The Kiss Quotient first!) and the brief cameo of Stella.

There were moments I became frustrated whilst reading how characters interacted, primarily Anna and her family, but that’s simply because of how much I cared for Anna. They made her voiceless and expected her to do whatever they wanted in the face of their opinions and wants, which pained Anna deeply. And I hated reading her pain.

Unlike The Kiss Quotient and The Bride Test, The Heart Principle deals with a main character, Anna, who is unaware they’re autistic and we follow the journey of their discovery and their diagnosis; the feelings and questions it entails, and the responses and attitudes that follow. The Heart Principle challenges its characters, and its reader alike, to face misconceptions of autism, of which was extremely emotional.

Combine this with the fact the story also explores the challenge of palliative care. Having literally experienced this in the past year, I can’t laud how much Hoang has done this justice. I felt the helplessness and isolation Anna experienced, and desperately wanted to help her. It was raw, gut wrenching and put frankly, powerful.

I personally would have preferred more romantic scenes between Quan and Anna to balance out the sorrow more, and more clarity on how things were left between Anna and her sister, which didn’t feel entirely resolved by the end.

All in all The Heart Principle is a true triumph of contemporary romance, giving a place for important discourse that if more widely understood, would make the world a better place, all the while illustrating a charming love story. It’s equally wonderful and tough, happy and sad, and entirely rewarding. I didn’t want to put it down, yet I didn’t want it to end. I won’t miss anything Hoang writes in future.

Thank you kindly to Corvus and Netgalley for an e-ARC in exchange for this honest review.

"The only good thing this broken heart of mine can feel is love for you.”

This book absolutely blew me away. I had previously read The Kiss Quotient and really enjoyed it. Hoang offers a refreshing take on the romance genre that challenges stereotypes.

Anna is an accomplished violinist turned accidental viral Internet sensation who is struggling to find her way through the next stage in her career, emotional burnout and family issues. When her steady relationship takes a turn for the unexpected, Anna meets Quan, a man with issues of his own who supports and encourages Anna to rebuild herself after a surprising diagnosis. Their battles for self-acceptance are heart wrenching and I felt like I learnt a lot about myself while reading this book. It definitely encourages you to reflect on yourself which made this book a powerful read. I was pleasantly surprised.

This story is heartfelt, moving and beautifully told- not to mention steamy! If you enjoyed Hoang's previous works or are looking for a romance with a strong story and interesting characters with ASD rep (brilliantly done) then you will love 'The Heart Principle'.

Helen Hoang’s books are smutty, cute, sugary, and I’m a total sucker for them. Reading the author notes at the end have given me an even greater appreciation for this third book in the series though - this one comes from a very personal place, and you can tell. I appreciate the care with which Hoang wrote about some very sensitive topics, and I also appreciate the fact nobody on the tube read any of the steamier parts over my shoulder 😅

Due for publication in August 2021, I’m very grateful to NetGalley for letting me read this before publication. I’ve enjoyed the previous two books in the series, but this one touched me in ways I wasn’t expecting. It felt honest, painfully so at times, but it was such a tender read that I found myself desperate to see how things worked out.
Our focus this time round is Quan, who we already know from the previous books, and his romance with violinist Anna.
Anna is a woman who sets herself high standards. She feels pressure to behave a certain way and her usual coping mechanisms are not working. Close to burnout it’s hard to imagine being at a lower point. But then her boyfriend suggests they take a break from each other and start an open relationship to help them figure out whether they’re really suited to one another. Perhaps it’s the way we’re encouraged to respond to him, but this just felt like a way for him to sow his wild oats without losing Anna. He never imagines she might be the one to move on.
When the open relationship thing is first introduced, she doesn’t know how to react. Her friends’ righteous indignation is just what was needed…setting things up perfectly for her to meet Quan.
Of course we want them to work out, and their relationship definitely ticks the boxes, but what I really loved about this was the way the pair of them together talked, shared their vulnerabilities and worked on ways to resolve problems. Quan is invaluable support for Anna as she comes to terms with her late diagnosis of autism, and how she manages the expectations of others while working out the implications for herself. At the same time, Anna is having to cope with the implications of caring for her father and how these new demands affect her and her family.
As I said, there’s a lot to digest here. Some issues are resolved, while others are not. Though there’s so much going on in this story it never felt cluttered or disorganised. Each strand combined perfectly to create a story that I defy people not to fall in love with.

The Heart Priniciple by Helen Hoang


‘“I just had a panic attack and hid from you in the bathroom for half an hour. You should never want to see me again.”

He stuffs his hands in his pockets and shrugs. “Just because something isn’t perfect doesn’t mean we need to throw it away. Plus tonight’s barely started.”’


I both love and loathe when a story hits too close to home. Sometimes certain elements within a book are just a little too painful to relive, even if it’s through fictional characters. It can be painful and awkward but it can also be a tool for healing, almost cathartic, to realise, appreciate and celebrate just how far the heroine comes, on her own terms, and in certain respects, yourself, as well.


The Heart Principle is definitely Anna’s story. Sure, she has the assistance of one super sexy, sensitive and sweet tattooed, motor-cycling riding hero to guide her, love her, adore and worship her, but ultimately Anna was the star of this beautifully written, at times heart-wrenching, masterpiece of romance writing.


Anna discovers in this book, by talking to her therapist, that she is most likely on the autism spectrum. This isn’t a spoiler, as it is discussed fairly early on and is covered in a huge portion of the story. Anna’s world is not only turned upside down by this revelation, it also exposes parts of herself that she didn’t fully understand or really acknowledge before. How she operates, why she is the way she is, feels the way she feels and struggles to overcome invisible factors, factors that most people don’t even realise are hurdles and tend to overlook. Everything finally begins to make sense for her and I loved that for her. Her pre-misconceptions about Aspergers and the autism spectrum are blown out of the water. Anna has a bit of an epiphany moment, so in a way this book is not only a truly magical love story between our two protagonists, it’s also about loving yourself, just as you are. Regardless of anyone else accepting your differences or comprehending them. You are the way you are and that’s just it.


‘I’ll draw a line around you and I’ll protect you and stand up for you and speak up for you when it’s right. I’ll keep you safe. And I’ll do the same for me. Because I matter, too.’



Anna was incredibly multifaceted. A well of confusion, pain, longing and frustration. An untapped well, who didn’t really know how to voice her thoughts or feelings. I loved that Quan was her rock. That her rebound, who was only supposed be a one-night-stand became something much more precious and treasured. Their friendship was a thing of beauty, a support system, no judgement, only confidence in one another. Anna and Quan produced a subtle yet seriously steamy undercurrent of sensuality, a spark that elevated their friendship to something more passionate and exciting. They were the markings of something profound and breathtaking. Quan had his own worries and problems, yet whenever Anna called, he literally dropped everything to get to her. It was a majestic balance between the two of give and take.

The Heart Principle is an intense, powerful and spectacular love story. Written with grace, passion and understanding, this is the kind of romance that will stay with you long after you’ve closed the cover. It’s a love story to those who are different, who are struggling. A love story to those who are going through the pain of caring for a loved one, who have lost loved ones, those who have been left behind in either a relationship or because of death. A testament to those who love you through your differences and grief. If you’ve ever experienced even an inkling of this kind of uncertainty and pain, then please read this book and let it soothe and heal you. You won’t regret it.

*Thank you to Netgalley and Atlantic Books for sending me an eARC in exchange for an honest review

As my friends probably know, I had a rocky relationship with the first book in this trilogy (I haven't read the second book yet) but this book really blew my expectations out of the water and pleasantly surprised me! This book had a more serious tone in comparison to The Kiss Quotient, and there was a lot more than just romance going on here - which I loved. There was so much rawness and vulnerability in this book and I admire the author for writing a story that seems so personal to her.

The exploration of topics such as being diagnosed with ASD later in life and trying to make sense of it, caregiving for a terminally ill-parent, cancer and the burden of expectations was really powerful and well done. I also really enjoyed reading about Anna and Quan's relationships, their journey to being vulnerable with each other and their individual fights for self-acceptance. This book was special.

🐙Book Review🐙

Hello Book Lovers! You know I'm not a contemporary romance reader and I mostly stay in my historical romance bubble that provides me with my needed escapism, though very few contemporary authors are on my radar and Helen Hoang is one of them. I love the way she writes stories and was over the moon when I received an ARC of her upcoming novel The Heart Principle.

Safe to say I cried so so much with this book, and kept staring at the ceiling when it finished, it was such a moving wonderful story about finding love and finding your own voice 🥺😭🤧💖

The book starts when Anna, our wonderful heroine is told by her boyfriend that he wanted them to go on an open relationship so he could see other people. She decides to do online dating where she meets Quan, (labelled now unofficially) the most amazing hero.
We've all come to know and love Quan in her previous books and he's even more than I could imagine.

What you can expect (might get a little bit spoilery):
🎻 Heroine is a violinist who is having trouble playing since her playing went viral on YouTube
🧠 Heroine is neurodiverse and struggles with her family accepting her as she is
🛵 Wonderful motorbike rides with Anna and Quan
🐙 Octupus and other nature documentaries that they watch together
💖 Hero is so head over heels with the heroine and accepts her as she is and helps her discover and enjoy her sexuality
🏨 Heroine goes through a journey of taking back her own power and voice her opinions and wishes, all of this through a difficult time where she's a caregiver to a parent

This book was a strong powerful story of Anna finding love and finding herself. I'd like to imagine Quan and Anna during winter in the kitchen cooking together and talking about nature documentaries. I know they'll be in my heart forever🧡

I absolutely loved this book. I think this series has gotten better and better with each instalment. The romance was incredibly cute and soft which I adored. Both Quan and Anna were interesting main characters to follow and I loved seeing their individual struggles. It was a bit darker and more intense than I expected due to the story with her family but I enjoyed that element. I thought it was an interesting thing to explore and I loved how it was handled. This is one of my new favourite romance novels and I highly recommend it to all.

Anna is a musician that has been feeling the pressure from going viral and to llease her boyfriend, so she agrees to an open relationship even though is not what she wants. Quan is the same confident and sweet but tough guy we met in The Kiss Quotient and The Bride Test, except he really isn't thay confident after some health issues he had to deal with. When these two decide they need a one night stand, they aren't prepared to find someone who understands them and makes them feel more themselves.

This book was truly amazing. I love all of Helen Hoang's work but this one got to touch very deep and important issues, not only about autism and masking, but about mental health in general and self-acceptance. The love story is still adorable and sexy (although nothing as steamy as The Kiss Quotient), but it's also such an important heart wrenching read, it was hard at times but I felt so proud of the characters, they had and amazing journey individually and as a couple, and Quan didn't fail to make me laugh! I truly adore this man.

Please beware trigger warnings!!!

I will start by saying that I adored The Kiss Quotient and gave The Bride Test 4 stars. So I could not contain my excitement that the third book would focus on Quan, who has always been a favourite of mine.
But I found it quite quite difficult to work out how I felt about The Heart Principle, particularly when compared with the first two books.
I'll start with what I enjoyed.
Seeing Anna be diagnosed on the spectrum, especially when I actually saw a lot of myself in her, was actually quite empowering. Again, the whole topic of autism was dealt with carefully and handled well.
The sexy scenes were sexy and explicit, much like in The Kiss Quotient (The Bride Test was a bit tame for me). And I found myself looking forward to seeing Anna and Quan be together without it being in the dark and both being open with one another.
But a lot made me struggle with this book.
I found it tough to keep reading through chapter after chapter of Anna caring for her Dad. I understand that this was to let us see how hard it was/how she was struggling. But it wasn't pleasant to keep reading seeing her Dad struggle with their decision to keep him alive like that.
I also hated her sister.
I feel like it was a wasted opportunity when it came to Quan too. He isn't given the same development or attention as Anna. His chapters feel quite surface level, even if I did enjoy seeing him interact with Michael and Stella.
I didn't feel like it went into enough depth when it came to what he was dealing with with life after a cancer diagnosis and surgery as well. And overall, his chapters were a lot less frequent or as long as Anna's.
He was just waiting around in the wings to eventually be with Anna and then waiting around for her to get better.
I still enjoyed it and felt like it was on par with The Bride Test, if not slightly less engaging for me. But I couldn't give it 3.5, which is why I ultimately went for 4 stars.
Thank you to Netgalley for providing me with an advanced copy of this book in exchange for an honest review.

Is 5 stars enough?! I think not. I have never had such a powerful reaction to a book before, ever since I finished reading I just can’t get it out of my head. This book was INCREDIBLE. Emotional. Raw. Honest. Sexy. 100% my book of the year and one of my favourite books I’ve read in a long time.

If you thought The Kiss Quotient and The Bride Test were emotional, you better stock up on tissues my friend. They were NOTHING compared to the absolute emotional wreck I became after reading this. Entire last 20% was just me crying intermittently and then sobbing when I got to the author’s note. Mission accomplished Mrs Hoang 😭

The book’s main protagonists include Quan (If you are a fan of the series you will know him well) and Anna. When their relationship begins, Anna is in the process of being diagnosed with ASD, so she approaches dating with a ‘no masking’ approach. I loved the result of this. Their relationship was so honest, open and sweet, and Quan was so loving and endlessly patient. He never once made her feel pressured, and I loved that he checked in when touching or holding her. I suspect he learned a lot from his brother Khai. Quan himself was experiencing his own personal struggles, and we saw him and Anna working to overcoming their vulnerabilities together. In between navigating a fair few heavy issues, Helen Hoang still manages to write the most sexy, electrifying chemistry with her protagonists yet. 🥵

What struck such an emotional chord with me in this book though, was how deeply personal and raw Anna’s journey felt. I think this switch to first person narrative from the usual third person really emphasised this, and even before I got to the end of the book and read the author’s note I suspected it was written from a personal place. The book provided an unfiltered look at what it was like inside the mind of a young woman struggling to come to terms with a late ASD diagnosis, and the crushing identity crisis that can come with. The writing made you feel as though you were in Anna’s brain with her, and you felt every anxiety, sadness and frustration along with her. When her family has a tragedy and she is pressured into doing more than she is able, her internal struggle was heartbreaking to read 🥺

This is a book that will stay with me for a while. It was an emotional rollercoaster to read but in putting herself out there laid bare; I believe she has produced her best work yet.

Many thanks to NetGalley and Berkley Publishing for the ARC of this book ♥

Words do not even begin to express how much I adored this book.

This story starts as a light-hearted romcom, but as any Helen Hoang veteran fan knows, her stories always retain a hidden depth to them that touches the heart in the exact right spot. To say Hoang has done it again is an understatement. What she's done with this book builds from The Kiss Quotient and The Bride Test in such a spectacular way I still feel emotional as I write this review. Following Anna and Quan was such a privilege and such an emotionally charged adventure; I laughed with them, I mourned with them, I fell in love with them (all within the one night in which I DEVOURED this book).

What I think solidifies this book as easily the best book of my 2021 reading so far is the way Helen Hoang balances creating this beautiful narrative with such incredible emotional depth with some of the hottest and heaviest scenes I've ever had the pleasure of reading. Romance readers, you will NOT be disappointed.

I will say there are perhaps some trigger warnings for ableism and suicidal ideation, so please do be aware of that!!

Ultimately, somehow despite the unimaginable hype I had built up in my head and heart for this book, Helen Hoang has managed to exceed these expectations in every way possible. A genuinely talented romance author whose work I will always look forward to reading.

Helen Hoang has done it again. My love for this series has grown a little bit more with each instalment but I have to admit The Heart Principle might take the spot of favourite. Anna and Quan's story was a roller coaster of emotions. I laughed, I wept, I swooned. I related to Anna so so much, and my heart broke for her on so many occasions.

I admire Helen for being able to write such intimate difficulties in a novel. I do believe it’s going to impact many of the people who read it in a beneficial way. I know it did, for me.

I think this must be a personal record for me - 3.5 hours from receipt until completion. It's fair to say I basically inhaled this book.

I discovered Hoang about 2 years ago on a "diverse writers everyone should read" type of list. I distinctly remember getting her first book at the library, and sitting in my car reading the first 100 pages. I only ended up going home because it got cold, and had it been summer I might have read the whole book in the library car park.

The Heart Principle is her third novel, and I loved it. Like her previous novels she writes about someone on the spectrum finding love. In this case it is a woman, Anna, who finds herself looking for a one night stand, only to meet the kind and understanding Quan. The book follows them both learn to understand each other, as well as dealing with Anna's family.

There is an authenticity to Hoang's writing - about Asian characters and families, and those on the autism spectrum - both aspects are part of Hoang's own identity. As someone in neither category, I think she speaks to me so much as she creates characters who are perceived to have 'oddities', but find kind, patient and loving people who embrace that. I think most of us can feel confused by others or social situations at times, but Hoang embraces the differences, and expresses the notion that there really is someone for everyone.

Thanks to Net Galley for an advanced copy in exchange for an honest review. I have never been so excited to be issued an ARC in my life.