Ruka this, Ruka that. Guys? Really? Now? We're in a life-threatening situation right now! Kazuya's roommate is gonna die if you just stay there! Remember? The coolest fish in this manga! She said that the temperature of water in her aquarium needs to be lowered! How do you even do that, though? I understand the heater, but is there some kind of air/water conditioner for aquariums to cool the water?