Kosegawa Shiromi♀

Shiromi is a third-year at Miyamori Girls' High School, and one of the three original members of its Mahjong Club. Shiromi is stoic, quiet, and apathetic. She is very tactical during her matches, contrasting her incredibly lazy attitude outside of them. While waiting for her turn, she has a habit of leaning all the way back in her chair. Whenever she starts contemplating on something, she likes to either bite her finger or put one of her hands over an eye.
Despite her apathetic exterior, Shiromi is very warmhearted and fond of her friends, offering them support and comfort when needed.

According to her teammates, Shiromi has a unique style. When she worries about her hand, it usually means that it's high scoring and she normally scores her points this way. She tends to slowly build her hand without opening it or calling riichi, leading to a distinctive play style. She often discards what others call risky tiles, but it hasn't been shown to ever backfire on her.