Mizuiro is part of Ichigo's friend group. He's got a boyish face and speaks softly, which honestly freaks Keigo out sometimes—there's something unsettling about how polite he can be. Early on, Ichigo actually mentions to Rukia that Mizuiro has a thing for older women, which becomes a running joke about his tastes.
Later in the series, his spiritual awareness kicks in alongside Tatsuki and Keigo's, letting him actually see when Ichigo, Chad, and Ishida head off to Hueco Mundo.
Despite being naturally good with girls and racking up dates constantly (which drives Keigo insane with jealousy), Mizuiro dealt with pretty serious loneliness before the friend group formed. His parents are almost never around due to work, which messed with his head and gave him kind of an inverted personality—he built walls around himself. Keigo was technically his first real friend, but even Keigo admits that Ichigo was the one who actually got Mizuiro to open up for real.
Content compiled by AnimeList.moe from publicly available sources.
