Is this Ai's sister? It looks like her... Any chance someone could translate the sign in the top panel? Presumably it's about the graduation, but if it mentions middle or high school that might be informative...
EDIT: Ai-chan's sister's middle school graduation indeed. And every guy in sight is hitting on her.
In other news, the second button thing is supposedly more for males, but given the position of that button I think I can see what these guys are after... A note on the concept from wikipedia:
The second button from the top of a male's uniform is often given away to a female he is in love with, and is considered a way of confession. The second button is the one closest to the heart and is said to contain the emotions from all three years attendance at the school.