So the question is, then: we know how foxy knows Suzuka and vice versa and Suzuka and Mikako being friends makes sense, but how does Mikako know foxy and/or sunshine boy? 

Addendum: I think Mikako is part of student council, and class rep, and just generally helps people out when they need it (hence the whole 'stop her from burning out' thing), so she could've met them through that?