Yi Tengcheng of ぃとぅまこと; Yi Tengcheng), the hero of Japanese game school era, the animation of the same name and subsequent games.

Due to the great influence of School Day in the field of Galgame, 0verflow released works such as Summer, Cross Day and Island Day after School Day, which respectively told the stories of people in other parallel worlds such as Yi Tengcheng.

Yi Tengcheng, a senior high school student, fell in love with Katsura Kotonoha, a girl in the next class, and became lovers with her. However, because he can't control himself, he is also dating a girl in his class, Saionji Sekai. However, it didn't take long for him to get tired of Saionji Sekai, and he began to attack all the girls who liked him. Later, when Saionji Sekai claimed to be pregnant with Yi Tengcheng's child, Yi Tengcheng's love rat nature was exposed.