Upon first glance at Chu-Bra!, one says to themselves "NO! This should not be, this is wrong on so many levels." This results from the fact that the main character Nayu, is completely obsessed with underwear, and having to deal with the knowledge that someone is getting turned on somewhere by 7th grade girls, which is really creepy. But if you get beyond this then the story is pretty mediocre. Some parts are original, but you can help but think that it has been done before somewhere else. They toy with the audience with love interests that develop between the characters that go no where, are implied but never grown upon, or are just completely stagnant. The story seemed pretty generic, but they added a unique twist with it with the whole "Underwear Society" perspective to it, which saves it from getting a much worse rating from me.
The animation seemed pretty cut and dry, and lacked inspiration. The characters didn't look particularly spectacular, and neither did the backgrounds. Its not good but it is not bad.
The main character, Nayu, seems like someone who should not be let out in public. She has an unhealthy fixation on underwear, which is a pretty creepy thing for a 7th grade girl to be obsessed with. Haruka and Yako become friends with her, only after accusing her of pretty much being a whore. Haruka is way too overly developed for a 7th grade girl, and it is suggested that she is lesbian. She seemed overly emotional, and would probably turn out to be one of those girls in high school that everyone pretends to like, but everyone thinks shes a bitch. Yako is pretty much your stereotypical case of napoleanic syndrome, with her small size and type A personality. Hiroko is a boy that finds himself in the "Underwear Society", and his only purpose is to set up awkward situations, and nothing more. Mizuno-sensei is pretty much clueless, and all she does is say nothing interesting and hit on Nayu's older brother. Overall these characters are boring and one dimensional, with quite a few worthless characters thrown in for good measure.
The whole series is just in general, uninspired, unoriginal, and most likely trying to get teenage perverts to watch and buy merchandise. I would recommend that you probably skip this one.