Chizuru Aizawa  

, 相澤千鶴

One of Chika's close friends in high school took swimming lessons with Tina and other classmates. Despite being scared of water at first, she overcame her fear and learned how to swim. She is more reserved than the others in their group and tends to feel overwhelmed by adult topics. Her thoughts are often preoccupied with perverted ideas (more so than the others), which can cause her to blush frequently and sometimes faint.