brother's fiance

Natsuo, a junior high school student, is no match for his older brother Masaki, both in looks and academic background. Saekano Natsuo secretly has a crush on Masaki's girlfriend Manami without telling his brother. One day, through Masaki's arrangement, Manami becomes his tutor, and Natsuo is excited, but... However, just then, he hears that Masaki and Manami are engaged. In his heart, he wants to bless their happiness, but when he hears Manami's moans coming from his brother's room, his lewd fantasies grow...