Lovely Complex is a love story between a boy and a girl. The girl, Risa Koizumi, is very high than the average Japanese girls. The boy, Atsushi Otani, is rather low than the average Japanese boys. The difference in height between the two protagonists makes these be mistaken for a comedy duo. The first opening theme song is "Kimi + Boku = Love?" by Tegomass and the first ending theme is "Kiss ~ Kaerimichi no Love Song~" by Tegomass.
If the top two players are competing over who will get engaged first, soon Risa's feelings for Otani emerge, complicating from that moment his love life. Risa falls in love with Otani and will do anything to make them understand, but Otani, as they say Risa and her friends, and will take a long time to understand the true feelings of the poor Risa.