Mikazuki Kiryuu

Mikazuki Kiryuu is Keita's underclassman and knew him from the same sports club at his former school. She actively pursues his attention and tends to jump to conclusions about situations around him. Mikazuki is also devoted to her older sister Yuuzuki, whom she affectionately calls her “otaku sister,” and is perceptive enough to recognize Yuuzuki's feelings for Keita.