Gakuen Tengoku

Oshino Makoto seeks to become a teacher to honor a promise to his childhood friend and first love, Koiwai Ayano, with whom he vowed to marry upon reuniting. After failing to secure a teaching position, he becomes a substitute at a private all-girls school managed by his grandmother. There, he encounters several students, including Narusawa Tsugumi and Asagiri Ayano, a teacher who looks like his lost love. He also becomes romantically involved with Kyoko, the substitute principal and his cousin.