Gibo: Stepmother's Sin

Synopsis

My name is Yusuke Yagami. When I was a boy, I witnessed something which no one should ever see. My own mother, locked in the throes of passion with a man who wasn't my father. Her adultery caused our happy home to come crashing down, and my father divorced her. Since those dark days, I've been mistrustful of what the concept of 'mother' really was.

Now, after so many years, my father remarried, and suddenly, I had a new stepmother, or Gibo.

The woman my father married was not old, but young, and beautiful. When I looked at Misako-san for the first time, I felt something move inside me. As the days went by, I found myself thinking of my new mother in ways that shocked myself. Could I accept this beautiful woman as my mother? After all, I found out what mothers are really like the day I saw their unfaithfulness. Punishment may be necessary...