This world has lots of problems, but after doing grown-up things all day, adults never have the time or energy to fix them! Kids, on the other hand, have LOTS of energy and lots more free time as well. That's why Yui, Sat-chan and Kotoha, three elementary school girls who live in Ueno, have formed COLORS, a secret organization that protects their town from whatever real or imagined menace happens to catch their attention. A monster cat who's also a cat burglar? They're on the case! A horrible surplus of bananas? They'll sell the case! And a bomb that needs diffusing? Well, they might need a little help on that one, just in case! The local cop might think they're a nuisance, but everyone else can sleep better tonight knowing these three heroines are saving the world in MITSUBOSHI COLORS!