Hiroko Oukubo 大久保 博子

Manager of the prefab team, one year ahead of Kō. Despite being called "chubby" by some of the players, she has a kind heart and is a very hard worker. Just like Risa Shido, she is also a former foreign exchange student. However, as opposed to the arrogant Risa Shido, she is humble and down-to-earth. She is the granddaughter of the Seishu board chairman, but she never takes advantage of that fact.