Yuka Ishikawa
Yuka had taken advantage of Karin since she had met her. Karin had liked her because Yuka was the only one who had spoken to her. Yuka relies on Karin for her grades and copying notes. She always makes fun of how uncute and dorky Karin is. While inviting her to a gokoun, she gets jealous of Karin and spills a drink on her new clothes. She likes to make Karin upset and gets jealous when Karin dates Kiriya, and locks her on the school roof. Ayase later stood up for Karin and she finally backed down, but Yuka still teases Karin, but less often.