I just discovered these fics recently, but I have to rec them out here because they're so sdafsdahjk amazing because everyone's so in-character.Level Up! Love!
Summary: High school life won't last forever. The two of you had better stop screwing around if you want to advance before graduation. Konami.
And the sequel:Next 2 Return the Revolution After Story
by the weluvgirlswithglasses.
Summary: So Konata & Kagami got together in Level Up! Love. Now, enjoy tidbits of their unique interaction as an established couple in the STUNNING sequel, NEXT2RETURNTHEREVOLUTIONAFTERSTORY. Look FORWARD to it. Who knows, a plot might even develop. Someday.