If you could start your life again, what kind of adult would you like to be...? Kogure Teppei is a police officer who is working in the community safety section of a local police station. Teppei's dream was becoming a detective of an investigation division at the Tokyo Metropolitan Police Department. Instead, soon after graduating from high school he becomes a police officer, and so he is faced with difficulties of finding the meaning of his current job. Thinking about his life, during his 35th birthday he suddenly time slips back to 1990, and finds his 13-year old self. He sees that young Teppei is not thinking about his future carefully, and decides to re-educate him so that he can have a wonderful life in the future. In order to make him go to a university to become a successful detective, he takes him to a tutoring school, and there he meets an English teacher Shoko, who believes that academic background is more important than anything.