The whole Time Travel episode. It begins with Takeru showing mad karate skills and brags that when he's a kid, he used to be a good looking model student who's awed by many. Cue Time Travel, and see that little Takeru is a complete BRAT, the reaction of his teammates are just priceless. And then in the end, the whole team got weird closeups to claim just how different past Takeru is with what Takeru described...
Akira: Oh jeeeez! You're such a trouble when you're a kid, huh??
Kenta: Takeru, I got your dirty little secret now! HAHAHAHA!
Haruka: Ooh, what a nasty boy. Flipping my skirt like that!
Momoko: "HAG!!!", or so he said. I'll never forget that, you know.
Takeru: Uh... that was just me being modest... After that I became a good boy, you know...
In the end of the 'girls gone bad episode', Haruka and Momoko are suddenly put on a gun behind their backs and told to strip... only to be stopped early, because it's the boys playing a prank on them. Pissed off, they chase the boys in a really hilarious slow-motion.