Like the title states, this is a story about the protagonist Tatsumi Nanami doing nothing but performing hypnotic m*sturbation. Generally, each story will conclude in a single chapter, but it will be organized so that at most a story will take 3 chapters. Though there is a female protagonist, she will generally be listening to a female hypnotic voice.
Also, the hypnotic voice that appears in this story is fictional, and does not exist in reality.