Gibo- Stepmother's Sin

Gibo: Stepmother's Sin (released simply as 義母 ('Stepmother') in Japan) is an adult computer game developed by Will and released in English in 2004 by Peach Princess.

In the game, the player assumes the role of Yuusuke Yagami, a college-aged male who, during his childhood, saw his mother having an affair with another man. As a result of what he saw (and the divorce that happened shortly thereafter), Yuusuke is distrusting of all women. His father, being described as a workaholic, has left Yuusuke to fend by himself. Yuusuke returns home one day to find a woman unpacking boxes in front of his home. She introduces herself as Misako, Yuusuke's new stepmother, and Yuusuke later meets his new stepsister, Shiina.

Gibo is an open-ended game, with different various endings the player can get if conditions are met. There are two meters on the screen- a lewd and a love meter. The higher the lewd meter, the more likely the player will receive either one of the more sexually explicit endings, or one of the bad endings. The higher the love meter, the better the chance for a good or neutral ending.

Gibo was also adapted into a two episode OVA 2001 by Digital Works. The same characters were used, though some of the character designs were changed for the two episodes.