久世 一真

In ~Yamana Gakuen Hen, Hikaru Hen~
The secretary of the private Yamana Academy's student council. He's been childhood friends with the protagonist since elementary school and with Hikaru since kindergarten. When it comes to sports specifically, his grades are exceptional. He's admired by his peers for his good looks and straightforward personality. He becomes lovers with the protagonist that he's long had feelings for, but...

In ~Yamana Gakuen Hen, Kazuma Hen~
The heir of the Kuse household; a distinguished household that goes as far back as the Meiji Era. However, he's not up himself about his pedigree and is an amiable person. He's better with sports than with studies and has been taught various martial arts by his father. Kazuma is popular with the female students but since he's too earnest, he's only dated one girl thus far. That said girl was stolen away from him by his childhood friend Saijou Hikaru. From the shock of losing both his childhood friend and the girl he loved, he vowed that he'll be "single for the rest of my life". However, in his story (Kazuma Hen), he finds himself in a completely unexpected situation due to Hikaru's machinations.

In ~Yamana Gakuen Hen, Yamato Hen~
The heir of the Kuse household; a distinguished household that goes as far back as the Meiji Era. However, he's not up himself about his pedigree and is an amiable person. He fiercely fought with his childhood friend Saijou Hikaru but in Yamato Hen, they've made up. He worries about the troubled protagonist.