Eighteen-year-old factory worker Makoto Katagiri enrolls in a correspondence high school alongside his sister Maaya, who failed her high school entrance exams. Determined to prove wrong those who mocked him for dropping out after middle school, Makoto finds himself in a diverse melting pot of students. On the day of the entrance ceremony, he has a dramatic encounter with Rio Aisawa, a stunningly beautiful young lady from a wealthy family.