Takeshita catching Yamada squirming suggestively during class.
When Yamada goes from hitchhiking to being in a car with a bunch of guys with guns to utterly destroying the competition with an airgun. Contrasted by Kosuda having a perfectly average vacation, it makes for one hilarious montage.
Nearly everything Misato does, but one scene in particular shows a number of the class guys having an Imagine Spot of her blurting out "You suck, virgin!" with a beaming smile on her face during a hypothetical sex session.