Osamu's right-hand man and oldest friend. He's got a warmer, more approachable personality compared to Osamu—the kind of guy who actually remembers to be nice to people. He and Shuuji are tight, probably closer than either of them is to most people.
He started out in the Izumokai Youth Division and eventually worked his way up to become Osamu's second-in-command, which honestly tracks given how long they've known each other and how well they complement each other.
Content compiled by AnimeList.moe from publicly available sources.