oni:
Their have been times when kotatsu Neko has gone swiming. Like the episode where ataru gets the fish stuck to his chest.
Revenge:
I love Kotatsuneko! I laught a lot with him when I saw the Obstacule Course Swim Meet... that cat is hilarious lol and the fights between Kotatsuneko and Ataru are EPIC, much better fights than Ataru vs Mendou.