A first-year who serves as the Student Council Public Relations. She is Masachika's younger sister who serves as the eldest daughter of the Suou house, whose origin was a former noble family and has shouldered the role of a diplomat for generations, becoming the heir after Masachika and their father left the family. She is a genuine, beautiful and straightforward girl, and enjoys teasing Alisa over her romantic feelings for Masachika, as Yuki's relation with him is not public knowledge. She and Alisa are rivals, and she occasionally torments Alisa for her performance to attend the Student Council. She has a follower, Ayano Kimishima.She used to have asthma when she was small, but claims that she has recovered and has never caught a cold since middle school.