有瀬 悠季

Yuuki is the classmate of Akihito and Riru, she is also in the same club as Riru and Reika, whom she idolizes. She isn't very talkative and gives the impression of being very cold.

She is sincerely friends with Riru and in Riru's route, she feels remorse at deceiving her confidence when she goes to sleep with Reika, with whom she is very in love. She is very afraid of losing her because she considers Riru as her best friend.