Tadakuni's Little Sister

She is a first-year high school student of Central High School and is hinted to be a lacrosse player. Being Tadakuni's younger sister, his friends simply refer to her as "Little Sister." Meanwhile, Yoshitake's Older Sister calls her "Mei." She isn't in good terms with her older brother and rarely talks to him. She is usually violent against the main trio because of their panty-stealing antics, but tends to eavesdrop on them and get swayed with their mischief. She likes Karasawa the most among his older brother's friends and sought for his help when she was in need.