None at all.

Some slashes and fights, but all of the violence is completely bloodless.

A couple of "damn"s and "hell"s. One use of "bastard" near the end of the series.

Not at all.

Some may find the glitchy game to be a bit eerie, and scenes where the characters are put into a coma are a bit creepy, but it really isn't a scary show. Compared to other anime, it's an extremely tame series.

Overall Rating: TV-Y7-FV (Edited Cartoon Network version) / TV-PG-L (Uncut DVDs)