I have learnt so much from The Heart Principle and Helen Hoang throughout my reading journey with The Kiss Quotient series, and I can’t believe it has concluded. I wasn’t expecting to read The Heart Principle and go through the emotions that I did, and I honestly an so happy that Helen Hoang wrote this book as she has. Not only does it make it feel all the more impactful, but it is a beautiful novel to the core.

When violinist Anna Sun accidentally achieves career success with a viral YouTube video, she finds herself incapacitated and burned out from her attempts to replicate that moment. And when her longtime boyfriend announces he wants an open relationship before making a final commitment, a hurt and angry Anna decides that if he wants an open relationship, then she does, too. Translation: She’s going to embark on a string of one-night stands. The more unacceptable the men, the better. That’s where tattooed, motorcycle-riding Quan Diep comes in. Their first attempt at a one-night stand fails, as does their second, and their third, because being with Quan is more than sex—he accepts Anna on an unconditional level that she herself has just started to understand. However, when tragedy strikes Anna’s family, she takes on a role that she is ill-suited for, until the burden of expectations threatens to destroy her. Anna and Quan have to fight for their chance at love, but to do that, they also have to fight for themselves.

Content warning: The Heart Principle deals with family abuse (emotional and mental), grief, cancer, stroke, home care of a loved one, loss of a loved one, parental death, and suicidal thoughts. These themes and situations may be triggering for some, and I advise that you hold off on reading this novel if you feel your well-being may be impacted in any way. This book will always be here for you to read when you are comfortable reading it. There is no rush.

This premise doesn’t do The Heart Principle justice, and I want that known right off the bat. There is so much more to the story – to Anna and Quan’s story – than a ‘string of one-night stands’. It is a story of two people with complex and confronting relationships with themselves meeting, attempting to ‘just get it over and done with’ to prove they are human, and failing to do so with such vulnerability and kindness. It is a story of acknowledging oneself as you are and finding the people who will love you as you are.

I love Anna and Quan. I love how they are awkward and unsure with each other, even though there are feelings between them. I love how their dynamic and relationship show how difficult it can be for someone to get out of their head during intimate times, and this isn’t just for people like Anna who are on the autism spectrum. Quan is just as susceptible to getting stuck in his head as a result of his thoughts and feelings surrounding his cancer, surgery, and post-op body. This not only helps to normalise the experience, but show that “normal people” can get mentally tied up too.

The situation with Anna, her burnout, her helplessness, and the thoughts she has when things get really hard break my heart. The fact that there are those in her family who loudly denounce her feelings and others who don’t stand up for her in the face of such ridicule angers me, and I know this isn’t a fictional occurrence for people. It becomes even more emotional upon reading the author’s note and finding out that not only is Helen Hoang autistic (something that didn’t click for me in The Love Quotient and The Bride Test), but she went through similar struggles as Anna with her mother’s ailing health while writing this series. When I read that, I almost cried. For me, it makes The Heart Principle all the more special and significant.

The Heart Principle is not an adult romance novel for the faint of heart, nor is it a contemporary romance novel to fill a sunny afternoon. It is a novel that will settle into your soul with a reverence, bringing reality to the forefront of your mind, and leave you with a renewed look on life, love, and family. I am so glad I read this novel, and while it may sound strange, I feel it will set me up for some eye-opening, emotional reads in 2026.