source: wikipedia_enSister Princess (Japanese: シスター・プリンセス, Hepburn: Shisutā Purinsesu) is a Japanese light novel series written by Sakurako Kimino and illustrated by Naoto Tenhiro that began serialization in 1999 and ended in 2003. In 2001, a manga series and a bishōjo game for the PlayStation were released. Sequels to the game were released for the PlayStation and Game Boy Advance.
Sister Princess was also adapted into two anime television series, both broadcast on TV Tokyo. The first series was produced in 2001 for 26 episodes. The second, Sister Princess: RePure, aired 13 episodes in 2002.