Mitsuko Murakami puts the passion to balloon in the hot-air balloon Circle "Airheads". The club gathered young people holding a variety of thoughts. But "Airheads" is disbanded not too long after. Five years later, "Murakami was in a traffic accident" starts to go around between the circle members, and for that reason the members reunite and hold again a large banquet in order to remember Murakami and the days in the Club.
