From Matthew"s Anime Blog: Daisuke is a 23 year-old new schoolteacher. He ends up being put in charge of a 3rd grade elementary school class since the previous teacher quit and in that class there s a girl who's quite a troublemaker, Rin Kokonoe. You could call her a masegaki (used to describe a kid that acts more like an adult in some ways), and she s also part tsundere (though more dere than tsun).
Kodomo no Jikan is licensed in the United States by Futabasha . Please support the authors and publishers that bring these great titles to us by buying the official books.