Ryo Shinichi was an expert masturbator who hung out in a certain online community called "Zzz Market". It was a place for sleep sex fetishists to indulge their fantasy.

Ryo: "Oh yeah. Time to jack off to some sleeping angels."

He noted a thread in the forums.
"SLEEP SEX IS REAL: How to be a minkan meister."
It seemed like the usual clickbait, but he read the strategy.
A light went on over his head. "This... this can be done!"

Ryo went all in. With his flawless minkan (sleep sex) technique, he was ready to slip inside the nearest schoolgirl!

[Edited from DLsite English]