I've read a number of reviews for this anime, and it seems that either you love it or you are quite indifferent to it. I must say that I'm in the middle. I'm not overly enthusiastic about it, but on the other hand I wouldn't consider it a waste of time. If you are into the more thought-provoking, slow-paced and realistic anime.
It's a slice of life anime, with a slow pace and a school setting. What's peculiar is the topic, as it deals with gender identity issues. The story's protagonist, a boy called Nitori, likes to dress in girls' clothes. His love interest is a girl who likes to dress as boy. His best friend also seems to have some gender issues. And they're all in the same class. I wouldn't say that is very plausible, but anyway. The way the anime deals with this controversial topic is never coarse or crude; the water-colour animation style very much reflects this, it's delicate and diaphanous and luminous. As for the sound, I just skipped OP and ED, and I never really noticed the background music - which isn't a bad thing, it must have blended perfectly with the story being told.
The initial episode was pretty confusing because it felt like all the characters were being introduced at once and I also had difficulty distinguishing them from a visual point of view. The two main protagonists are quite androgynous - purposefully so - and at the beginning, when you don't know who they are and you still know nothing about the story, it's hard to say who's who. Like other reviewers have mentioned, initially you don't really like Nitori, he comes across as a kind of wishy-washy insipid indecisive character, but as the anime progresses he does develop - even though I never did really feel I could relate to him; and that's got nothing to do with the issue in itself. For many episodes, for him it's just about dressing as a girl. It's only after someone else asks him some questions relating to how he feels about his identity that he starts to consider that aspect. After a little reflection, I think what I didn't like about Nitori is a certain shallowness, a lack of depth that made me unable to relate to him. And as for the other main character, she's more determined in wanting to dress as a boy and rejecting all the girly aspects of herself, but that's as far as it goes: what she wants or feels isn't analysed much more in depth. So maybe something is lacking there. It's also true that we're talking about kids in middle school, so it's normal that they are confused. But still. It's realistic, but up to a point. Nitori at a certain point decides to wear a girl's uniform to school; he's aware that he's going to undergo some criticism and unpleasantness, but sticks with his decision and then is obviously put off by how other people react. Even so, I'm pretty sure in a real-life situation the bullying would have been much much worse. A nice thing about the anime is how nearly all of Nitori's friends accept and support him in a really mature way - but this too, how realistic is it? As for the other characters, they're a mixed bag, some portrayed better and more convincingly than others. Looking back on them, maybe Nitori's best friend is a more persuasive and empathetic character; that's how I perceived him, anyway. The ending can't be considered a real ending as nothing is resolved, but the way it's told makes it acceptable. I mean, all the input is there for a second season, but even if it stops just with the first season that too would be ok, you wouldn't feel cheated.
Overall, it's an anime that deals with a difficult topic in a delicate, if maybe too idealized, way. I like anime that make me feel something, that deeply move me. And I think this is exactly what this anime lacks. It didn't make me smile nor did it make me cry. It was interesting and well narrated, but up to a point. And I can't relate that much to the main protagonist. So in the end it's a pretty unexceptional anime to me.