No sex, nudity, or even fanservice whatsoever. However, there are a handful of mildly naughty jokes. Nothing remotely obscene though. Probably the crudest jokes in the entire series is a running gag that high school boys like to wear their sisters' underclothes (no nudity, but we occasionally see boys walking around in bras and wearing panties over their heads like goofballs).

No actual serious violence or peril, however, there are multiple instances of slapstick violence (often involving small traces of blood and nosebleeds). Teenagers are also seen simulating fantastic (imaginary) battles in hyperactive ways. For example, at the beginning of the first episode, we see some Gundam (basically robots) launch rockets at three high school boys (though, this is totally fake and they aren't hurt at all).

Some uses of "h*ll" and some other mild language. No strong language or anything of real concern, though.

Some of the aforementioned imaginary battles can be mildly intense. For example, one of the teenagers briefly pretends to be some sort of demon lord (who looks kind of creepy from the perspective of the teens' imagination). But it's all intended to be fake and done in good humour.

Overall, TV-14 is a bit harsh for this show. TV-PG would've been a much more fitting rating, based on the content discussed.