Azusa describes him as a blonde shota.
Nagisa teases the people around him, even if something terrible happened to them (case in point: the incident with Homura). He later reappears as a quiet guy who's in the yakuza.
Akira has a crush on Nagisa and confesses her feelings to him, to which he only gives her his phone number.
He always nags her about her name.
Masehiko is Nagisa's superior and probable boss of the yakuza.