This autobiographical novel by the author, born in 1980, depicts a situation in which a generation that has lost confidence in their masculinity sympathizes with criminals because of their rebellion against society. The author, who debuted at a young age, was married, had a son, and was leading a peaceful life. One day, he is contacted by his former editor, who has returned from Paris for the first time in several years, and is asked if he would like to finish a novel he had previously put on hold. It was a novel about a real-life serial killer of the same generation, but it had been put on hold because the editor in charge had left Japan. However, the author no longer had the same interest in serial killers as he had in his youth. This was because he was a good father and lived happily with his family. However, as he held meetings with his editor, he gradually began to question his current happiness within the family. In order to digest the residue of youth left in him, he regains the youth that should have been lost, while accepting his own current situation through his band activities as a new challenge and his examination of serial killers. This work has resonated with contemporary Japanese men who find it difficult to live amidst the changing roles of the family and men.