Yousuke is a college-aged student who became emotionally damaged in youth from
seeing his birth mother repeatedly engage in adulterous acts while his father
was away. Now, his father has decided to remarry. His lovely new wife, Misako,
is moving with her daughter into the house Yousuke previously inhabited alone.
Will he accept her as his mother, or use her to have his revenge on the mother
who tormented him for so many years?

Gibo is a Japanese adult visual novel. The plot proceeds at its own pace,
pausing occasionally to allow the player to intervene by making a decision,
resulting in a story branch. There are over 40 such decisions, leading to 13
different endings, some “good” and others bad. The game contains Freudian
imagery and graphic depictions of sex.