Ruri Mihashi ( 三橋 瑠里 Mihashi Ruri ) is the cousin of Ren Mihashi and the niece of Ren's mother. She lives in Gunma but sometimes comes to visit.
When they were young, Mihashi and his family visited Ruri and they often played together with Kanou, leading him and Mihashi to develop a friendship.
During his middle school games, he told Ruri to not attend and thus did not tell her when the games took place, embarrassed and ashamed because of his failures.
She cheered for Nishiura during their game against Tosei, surprised by how Mihashi had skillfully played during the game.
Ruri enjoys calling Mihashi by the nickname Renren, much to his dismay. Mihashi's teammates even teased him upon hearing Ruri call him by that nickname.
She has a younger brother named Ryu. He went to cheer for the Mihoshi team at their game. In particular Kanou from across the street.