Shinshokukan | 浸触姦

The main character, Kiyohiro Meguro, is a college student who lives a lethargic and self-deprecating life. He has a hard time going to school, and is taken care of by his childhood friend Konatsu Hirono. He was living a lazy life.

At that time, Kiyohiro's brother, Jiro, a biologist and his girlfriend. He returned from overseas accompanied by Sayama Milano. From this day on, Kiyohiro's living environment changes to a lively one that mixes Jiro, Milan, and Konatsu.

Kiyohiro is intensely stimulated by Milan's uninhibited behavior in both speech and sex. He saw Milan having sex with his brother and was seduced by Milan. And he forms a relationship with Konatsu, whom he has secretly been in love with for a long time... And Kiyohiro's daily life changed drastically.

One day, Kiyohiro notices that his brother's behavior has changed. Jiro was born with a weak body and a gentle personality, but Milan makes him drink. His appearance began to change dramatically, perhaps due to the suspicious drug.

And Konatsu's recent behavior as a helper at his brothers pharmaceutical company is also strange...

Kiyohiro is distrustful of his older brothers...especially Milan.

Could it be that the cause of all this lies in the pharmaceutical company that Milan, his brother, and Konatsu work at? I became suspicious and started investigating.

Finally, a "creature" that he had never seen before begins to erode the area around Kiyohiro.

A tentacle creature that overruns Milan and even Konatsu with its reproductive instincts. The harrow is like the mating of a horrifying and violent beast that doesn't seem to belong to this world. These girls lose their bodies and minds and become female.

Research on Milan and Jinro, and the transformation of the kind older brother. Kiyohiro, who doubts the relationship between these and tentacle creatures, is forced to make a choice...

Will my sexual desire be swallowed up by the enchanting sight of the tentacles... Or will he rescue Konatsu and the others and find out the truth behind this commotion?

What answer will Kiyohiro choose?