Mizuki Mukubayashi (椋林 みづき, Mukubayashi Mizuki) is a major supporting character and romantic foil in Yowayowa Sensei. She serves as the Co-Class Representative alongside Akihito Abikura. Operating as the flagship gyaru of the series, she injects high-level extroversion and unpredictability into the classroom dynamic, frequently compromising Akihito's efforts to keep Hiyori Hiwamura's secret hidden.