Three friends, Sen, Kotake and Nojima, discuss jumping off the platform in front of a train — but not dying. Sen, a guy who just smiles and is cheerful, later kills himself by jumping off his apartment building. His father is desperate to know to how he died, so he takes the students in Sen's class hostage. Fumika shows up and delivers a letter from Sen to Kotake; the letter reveals that Sen jumped because he was in the mood for it. Nojima believes that Fumika is Fumika Mikawa, a girl he knew from junior high who shot her own father, and runs to the rooftop to confront her.