Fumi Nishioka

She is a second year high school transfer student, which just transferred to Kurakado High School. Nishioka came from a poor family, thus she made marrying a "wealthy man" as her life goal in order to get to the better side of life. Because her relatives suddenly disappeared one night and left her with only a message, and her parents both passed away a long time ago, she ended up sheltering in the old campus, thus the beginning of the story. She finds Horikita as a strange guy.

Called by Sakaguchi's 'heart' she enters the Gate of Hazama in the old school campus, where she eliminates a 'parasite'. Due to her family and living situation, and defeat of a 'parasite', Kouichi offers her the job of working as a housekeeper in the mansion he shares, and helping Kyuutarou with his responsibilities.