Chisa has short brown hair and is average in height and build, being shorter than Nanaka and Azusa. She has been described as cute by other characters and Iori has made several comments about her body, particularly her butt, which he calls spectacular. She has the second smallest bust among the female characters and though she is conscious of it, she isn't as concerned about her chest size as much as Aina.
Chisa appears to be more level-headed and serious compared to the other characters. While the rest of her class fools around, she takes her studies seriously. She rarely takes part in the diving club's shenanigans and is usually seen sitting off observing. She loves diving and is usually the most eager in anything related to diving. She has clear dislike for rowdy behaviours (that most of her friends have) and can be quite hostile, especially when it is directed towards her.
- Toshio Kotegawa: Chisa's father. Not much is known about their relationship as they rarely interact with each other.
- Nanaka Kotegawa: Chisa's older sister. She has a close relationship and seemingly looks up to her though she is oblivious to the fact that Nanaka is a siscon.
- Iori Kitahara: Chisa's cousin. She has a clear dislike for his tendency of being roped in most of PAB's shenanigans, particularly being drunk and naked. Despite this, they are capable of working really well together and she can sometime show a level of compassion towards him especially when it comes to his interest in diving. It is later revealed that they are not related by blood since Iori's father is adopted by her maternal grandparent.
- Shiori Kitahara: Chisa's younger cousin. Not much is known about their relationship other than they are quite close. Like Iori, they are not related by blood despite being cousins.
- She is one of three female students in her class and is idolized by her male classmates due to the lack of females in her major.