Масаси Ирума

Masashi is a 7-year-old boy whose father owns an apartment complex. He used to be friends with Isahaya but they stopped meeting after Isahaya's grandfather, a rich business owner whom Masashi's father owed money to, hired yakuza to intimidate Masashi's father into giving up the building. Because of this debt and the yakuza chasing out all their tenants, Masashi hates rich people and yakuza. He initially doesn't think much of Tsukasa when her brothers move into the building, but they become friends after she and Ryuuji help sort out the loan situation.