Yumi, a writer of a science magazine, witnesses a mysterious death of a high school girl who received a "one missed call" from her own cell phone, two weeks in the future. The disturbing message on the cell phone turns out to be the screams of the victim.

Misaki decides to join the Brass Band Club having heard of its prestigious past from her father, a former member. However, Misaki finds that much has changed and the club is now full of dull and inactive students. Misaki determines to do her best to return the club to its glory days, but she must help many of the students overcome their personal problems.

Takako Meguro, a typical office worker known to her friends as Medaka, starts a new career as a night school teacher when her company restructures. At first, she's not so crazy about her new job and gets by with a minimum of effort. But as she continues, she finds out it's quite a challenge after all. Her students range from a high school dropout to a salaried worker, and also include a self-employed fellow, and a cabaret hostess, in short, a motley crew! What's more, half of them are older than her and, to make matters worse, one of them is a elementary school classmate. But a certain turn of events results in Medaka's becoming a really dedicated teacher! Although she's surprised herself at this change of character, her trials are just about to begin.