is a Japanese manga series written and illustrated by  manga author Kaworu Watashiya. The story revolves around a grade school teacher named Daisuke Aoki, whose main problem is that one of his students, Rin Kokonoe, has a crush on him. It was first serialized on May 22, 2005 in the Japanese seinen manga magazine Comic High!, published by Futabasha. At one time, an English language version of the manga was licensed by Seven Seas Entertainment for distribution in North America under the title Nymphet, but the Los Angeles–based company ultimately decided not to publish it due to controversies over its content. An anime adaptation of the series aired on Japanese television between October 12, 2007 and December 28, 2007. While content of the broadcast version was sometimes heavily censored, the DVD releases of the individual episodes remain unedited. A second anime season was released as four original video animation episodes between January and July 2009. A third original anime DVD to be included with the limited edition of the ninth volume was announced on the cover of the manga's eighth volume in May 2010, and was subsequently released on January 21, 2011.

Kodomo no Jikan (jap. , dt. „die Zeit eines Kindes“) ist eine von der Mangaka Kaworu Watashiya geschriebene und illustrierte Mangaserie.

Kodomo no jikan (こどものじかん, Le temps de l'enfant), parfois abrégé en kojika (こじか), est un manga créé par la mangaka Kaworu Watashiya depuis le 22 mai 2005 dans Comic High!, un magazine seinen.