Largo's class
Largo teaches an English class at Shiritsu Daitou High School, after a case of mistaken identity by the headteacher when Largo disguises himself to follow Miho.
Two of Largo's students include Miho and Ping, which is where they meet after Largo jumps out of the window. The rest of class have no love lost for Miho, and are familiar with her acting 'creepy' and presumably antisocial.
Junko is another student and the class president (iincho). Some further students have been named, and several students told Largo what they're good at, so we know one is on the basketball team, one of the boys builds realistic models of WWII aircraft, another boy collects and watches American sitcoms, and a girl has over 350 people on her buddy list.
Lessons largely involve Largo teaching the students "l33t skillz" such as controller technique and field trips to the 1 Yen Arcade.
The only class member named that isn't even a minor character would be Junko's tall friend Ninamori.