Kodomo No Jikan (Nymphet) manga has not been published in English because it is said to be too controversial. Seven Seas Entertainment has decided to cancel the publication of Nymphet, Once they came to the conclusion that Nymphet is too inappropriate to have in the U.S. Which I think is untrue because "Nymphet" is not real it is a book. Also their is nothing very explicit in it. There are much more explicit manga's out their like: Hentai, Yaoi, Yurri and those are published in the U.S. If people do not want to read "Nymphet" then they shouldn't buy the book. But not publishing it because a few people complained about it even though they have probably never read it is stupid. Just because they don't like it doesn't mean they have to ruin it for everyone else.