Tsubasa Yamabuki  

, 山吹 翼

A classmate of Shiratori who is always trying to attract high school girls and young women but has no interest in younger children or those who are flat-chested. He stumbled upon Shiratori while dressed as a girl due to a prank, fell deeply in love with her, and gave her the nickname "Reiko" without realizing that she was actually Shiratori.