Sacchan, Yui and Kotoha are here to protect the city, solving mysteries and battling enemies with help from their friends. But their quest isn't an easy one as their arch-nemesis Saitou, the violent police officer of Ueno, meets them at every turn.
For anybody worried about da loliloli, this series doesn't sexualize these young girls (I know--weird, right?). It genuinely feels like it's just showing the innocence of children. It does rely on the girls' cuteness factor for a lot of the humor and general appeal, but (at least personally) I didn't interpret it as a sexual type of cuteness--more like the cuteness you get from animals or something. I think all three of these girls are vital to keep the story entertaining. Sacchan (Yellow) is a playful, exuberant girl who likes saying "poop" and uses blunt, gross-out humor. Koto (Blue) is a quiet, gamer girl who thinks of violent and gory things, laughs easily at punny things, and likes stepping on people's heads. Yui (Red) is an honest and conscientious girl who is horrible at lying, runs slowly, and often acts as the "straight man" in their jokes. Together they are The Colors, who have sworn to protect the peace and safety of their town. They'll find "cases" (which are obviously not actually cases), but then get distracted by something else and just end up playing or something. It's also funny seeing some of their violent and destructive fantasies, considering they self-identify as the heroes. They interact with some of the shopkeepers and others in the town square, most frequently the old man, Nonoka, and the police officer Saitou. They spend some of their time in the shed they use as their base, in the local park, and in other areas around town. We never see their homes or family life and barely see anything related to school. It's very much just a story about their playtime with their friends. There isn't any character development in the sense of them changing or growing, but we do get to know these fun personalities--their quirks and flaws--as the series goes on. I love this series. It brings a smile to my face and I find it hard to put down whenever I pick it up.