Both the Please Teacher and the Onegai Twins manga were adapted from popular anime series, a reversal of the usual pattern in Japan where a popular manga typically inspires an anime adaptation, but this anime-to-manga method has produced some major manga hits in the U.S. such as the Cowboy Bebop, Wolf's Rain, and Samurai Champloo manga series, all of which were based on anime.
Bandai Entertainment released both the Please Teacher and Onegai Twins anime series in the U.S. (see "Bandai Has 'Please Twins'"), and both romantic comedy series were very successful. In Onegai Twins a high school kid finds that two attractive girls are both claiming to be his long-lost twin sister, and he has to determine who the real sister is, primarily because he really wants to date the girl to whom he isn't genetically related.