To be fair, when I first started reading Keigo Higashino’s Secret, I was not immediately captivated. I knew Keigo Higashino as a writer of mystery novels, so I thought this book would follow that trend. I didn't expect a novel bereft of murder and deduction, and I was not anticipating a thought-provoking exploration of human nature and love.

The novel depicts a mother (Sugita Naoko) and daughter (Sugita Monami). Following an accident, when the mother's body dies, her soul is transposed into her daughter. This choice of topic did not bring me any surprise, but the more I read on, the more heartbreak I felt. In the middle, the male protagonist (Sugita Heisuke) and the female protagonist (the daughter possessed by her mother) encounter various challenges. One of the obstacles they face is divergent physical trajectories. As time passes, one becomes more and more beautiful, while the becomes older. According to the novel, Heisuke is 40 at the time of the accident, and his daughter is 11. Heisuke experiences a mid-life crisis, while his daughter is entering the most exciting age of her youth. Like most people, she does not want to waste the best years of her life on a person who is getting older and older. Inevitably, emotional "cheating" occurs. As she begins to regret, "her daughter's soul gradually begins to recover and finally replaces her mother’s." The story develops to the point that her daughter marries another man.

If the book were like this, Keigo Higashino would not have won the 52nd Mystery Writers of Japan Award for Best Novel for this book. Before her daughter's wedding, Heisuke discovers that her daughter knows the secret that only he and his wife know. What is the final truth? Is this woman Naoko or Monami? Keigo Higashino does not give a clear answer in the book.

Before I reflected on this question, I looked up the background of Keigo Higashino. In 1997, he divorced his wife of 14 years. He spent the next year developing his emotions and finally wrote the book Secrets. This book is about both Heisuke's release and the author's own release. It is also the author’s interpretation of his 14 years of marriage. Two people who were once in sync are no longer in the same pace: as fate and life push Naoko forward in a more hopeful direction, she no longer wants to stop and wait for Heisuke. She disguises herself as Monami in order to keep Heisuke from being upset, so that their previous marriage can come to a great end. The most heartbreaking aspect is that Heisuke does not remarry. Instead, he agrees to give Naoko a new life. He knows that the best expression of his love for her is to let her go. Heisuke is the author himself, and although he is hurt by the divorce, he is relieved. He uses this novel to wish his ex-wife, whom he once loved but can no longer walk in the same pace with his life, a good future.