Mao-chan goes on too long. It’s based on a clever notion and is executed with considerable charm, but the writers weren’t inventive enough to keep it consistently interesting through 26 half-length episodes. The story meanders through many standard anime situations: the sports festival, the beach episode, the hot springs episode, the bunny suit, the maid uniform. They’re not complete wastes of time — the beach episode is one of the better ones, in fact, though not because of the beach — but they mainly serve to let us spend time with the girls rather than advance the story, and Mao and Misora aren’t particularly interesting characters. The series would have been better overall had it been shorter and more focused.
When the Fnools invaded Earth, they disguised themselves as two-foot-tall real estate salemen, figuring that no one would take them seriously until too late. ((See Philip K. Dick’s “The War with the Fnools.”)) The aliens in Mao-chan adopt a similar strategy: by assuming mercilessly kawaii forms, the invaders make the Japanese defense forces reluctant to engage them in combat, lest the human soldiers be seen as bullies. The Japanese fight cuteness with cuteness: the head of the land forces enlists his eight-year-old granddaughter, Mao, to battle the invaders, arming her with a baton, a full-size model of a tank, and a clover-shaped pin that transforms her into a not-terribly-competent but very cute mahou shoujo. Mao soon is joined by a couple of other eight-year-old girls: Misora, representing the air force, and Sylvie, representing the navy, both recruited by their doting grandfathers. Mao and Misora are ordinary grade-school girls, as kids in anime go, but Sylvie is distinctly Osaka-ish.