Sora Aoi is Tsumugi, a typical Japanese girl. She''s in love with her teacher,
Shin. One day, Tsumugi witnesses Shin and another teacher holding each other at
school. Soon after, Tsumugi goes to Shin''s house to seduce him. Shin gradually
starts falling for Tsumugi. At the same time, Tsumugi attracts her classmate,
Kosuke, who wants to be a triathlete. Tsumugi soon begins falling for Kosuke.
Now Tsumugi faces a dilemma: who will she stay with?