Titre original : The Day I Vow to Heaven
Haruko Amaya arrives early to accompany childhood friend Takeru Ohyama to his first day at Tenbi Academy. After she excuses herself to prepare for the induction ceremony, Takeru wanders around to take in the view, and witnesses a curious confrontation between two female students before having a run-in with Kodama Himegami. At the ceremony, Kodoma requests a duel with her enemy Takeru, intending to kill him, but Inaho Kushiya intervenes to save her fiancée. All four become roommates living in a triple.