Arimi Suzuki

She convinces Yuu to be her "boyfriend" for three months, during which they act as a couple on a trial basis. Arimi attempts to make Yuu to fall in love with her during this time, but fails. At the end of the three months, he still thought of her as a friend. After Yuu joined Toryo High School, Arimi and Yuu lost contact, however, Yuu keeps a picture of them together in his diary, for unknown reasons.