Ogawa is a classmate of Tomo Aizawa and best friend of Mifune. Ogawa, along with Mifune, got jealous of Tomo for spending too much time around Misaki. They both confronted Tomo, but she intimidated them. After telling the girls that she would help them get closer to Misaki, they become somewhat friends.

(Source: Tomo-chan wa Onnanoko! Wiki)