Chisa Kotegawa is a supporting character of the manga series Grand Blue. She is Iori's cousin and a first year Mechanical Engineering student at Izu University.
Chisa appears to more level-headed and serious compared to the other characters, she has clear dislike for rowdy behaviors and can be quite hostile, especially when it is directed towards her, especially with Iori. She rarely takes part in their drinking or their other crazy antics and is usually seen sitting off the side as an observer. She loves diving and is usually the happiest when doing the activity or looking at diving equipment. Chisa is one of three female students in her class who is idolized by her male classmates due to the lack of females in her major.
~!It is later revealed that she and Iori are not related by blood since Iori's father is adopted by her maternal grandparent.!~