Due to the emblem curse (which I guess makes your skin burnt or something. I'm not sure, I don't think it's ever explained) many students in the school are just wrapped up in bandages and no one seems to have any reaction to it. But only this guy gets a cheese steak.
Also, this isn't really a joke...this is basically what happens. Lisa actually knows Eikichi's childhood crush was the girl he met earlier and is just like "Nobody tell him. It'll be funny."
According to the P2 EP Extra disk anime concept trailer thing (or whatever that was) all the students faces are melting I guess maybe perhaps http://www.youtube.com/watch?v=tPIo5k2Zqu8
Didn't Kozy ask Lisa not to tell Eikichi about her? I'm sure that's what happened in game. I won't lie though, it would have been funnier is this was true.
Also, this isn't really a joke...this is basically what happens. Lisa actually knows Eikichi's childhood crush was the girl he met earlier and is just like "Nobody tell him. It'll be funny."