Hibino Akira

Nao Yoshino is a girl who fails the entrance exams of her target high school. She winds up enrolling in a technical high school called Kenritsu Asuka Kōgyō Kōkō, also known by the nickname "Asukō". Out of the 148 entering freshmen, only three are girls, and Nao is the only one in her class.

Shinichiro Hanasaki, a former detective with the police department, is currently engaged in running a nursery called “Smiling Garden.” He wishes to help poorer families and single parents by offering very low fees for childcare, but this leaves the nursery struggling financially. To replenish the budget, Shinichiro decides to open a private detective agency at night.

When I was 17-years-old, Maria was a college student and worked as a private tutor. Her student was me. She left a last message to me, "when you graduate from college and become an adult, can you become my lover?," and then she disappeared. 10 years later, I meet her again. She is now a suspect in a serial murder case and I am a lawyer.