Asobi ni Iku yo! EP8 - We Had A Duel

Aoi and Manami decide to have a showdown in a nearby forest to settle their differences, but their match is cut short when they must join forces to defeat some assassins sent to take both out, the winner was therefore Manami. In the end Aoi had to pronounce KioKio Kun but doesn't take notice at all Manami then acted violantly.