Tomizawa Erisu

She is Fuuka's classmate and close friends. The daughter of one of the richest family in the countries and a bona-fide 'Ojou-Sama'

She has a refined demeanor, but her character is hot-blooded and she hates to lose.
Although proud of her bloodline, and a bit of an arrogant attitude, she is still a good person despite her sarcastic comments.
Erisu and Fuuka compete with each other as members of the swimming club.

Once she notices the protagonist humiliating Fuuka, she ends up being involved in the family's training drama.