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.
The only class member named that isn't even a minor character would be Junko's tall friend Ninamori.