Ai Sugimoto
Sugimoto is a co-worker of Nakamura Hiro. She was in love with him and once told him she was Kuukai-san (the name Mao uses when she writes her cellphone novel). She later regrets her mistake, apologizes and tells Hiro the truth. For a short time she was also friends with Mao—knowing she's the actual Kuukai-san—but later they talk less when Sugimoto starts lying. She has a supporting friend named Ruirui whom she met online four years ago. She assumes Ruirui is a girl because Ruirui often gives her love advice and always cheers her up. They have the same interest: Date Masamune, whom they call "Maa-kun." She later falls in love with Ruirui.