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. Gameplay The premise behind Sister Princess is that an ordinary young man (the player) is made to live with twelve lovable little sisters, each with their own distinct quirks and personalities. The game itself plays out like a dating sim. Players have about a month to spend with the sisters with each day broken up into three segments: first is the free time period before noon, followed by the period after lunch and ending with another period of time before bed. During day time, the player can choose which of the girls he wishes to escort to school, if any. The period after lunch is similar to the one in the morning, with additional choices which allow the player to go to various places in town besides walking home with one of the girls. Every night before bed, the player will be allowed to check his e-mail and send replies. As the player continues to interact with the sisters, their reactions to their big brother will change accordingly until the ending. There are two different endings for each sister: the normal ending and the "non-blood relation" ending. As the name would suggest, the special ending reveals that the brother-character and sister are not actually related by blood. In the case of some of the older sisters, this can lead to the protagonist and "sister" marrying one another. In the original Sister Princess, the player can see two different endings for each sister, but Sister Princess 2 has four endings for each sister. The first two were the non-sibling relation and siblings-together ending and, if the player chooses one sister in the beginning but ends up with another sister, either of the other two endings for the first sister who the player does not choose appear ("non-blood relation" ending and "still brother and sister forever" ending also) but with a different story. For Sister Princess