Naoki was a regular schoolboy. One day, after reluctantly following his otaku friend around town while not sharing his interest, he spots on a shelf of the game corner an eroge about having sex with your mother.

Normally Naoki wasn't interested in such things, but the idea of "mother sex" awakened a deep lust inside of him he didn't know before...

Simply the word, "mother", aroused an immoral instinct...