或ル家族ノ姦系図

A pervert who loves bondage, Kyoichi Mitsugi's life is a story of a young man who has a perverted nature, whose life took a sudden turn after his father's sudden remarriage.

His mother and sisters, with their haughty attitude and self-importance, had been living a carefree life until one summer day, when Kyouichi's frustration and desire peaked. He pushed down Mizuno, his mother, in a fit of lust, and was kicked out of the house.

Since then, our protagonist spends the night in a storehouse in the garden. There, he discovers a manual and a variety of lewd implements that belonged to his grandfather, Kyorakusai. As he looked at the manual, he felt a burning sensation welling up inside him.