Toshiro is a totally ordinary office worker blessed with a wife and child.
One day, he receives word that his mother has suddenly passed away, and he returns to his hometown with his family.
When he gets there, it turns out that his father got ahead of himself, and his mother is very much still alive.
Since he came all the way there, he decides to stay with his family for a little while to visit.

While there, he happens to run into his childhood friend, Akiho.
Despite how long it's been, their friendship is rekindled instantly, and when the conversation heads in a dirty direction, Akiho says something shocking.

Hey, it's been a while, so why don't you show me something nice? It'll be fun.
You showed it to me before, so it should be no problem, right? I bet it's pretty hard!

It's true that they used to show each other their genitals as a joke.
But that was just because they were too young to know any better.

You had too much to drink, didn't you? Here, I'll take you back to your place, so let's go.

Since Akiho seems to be pretty drunk, she won't listen to Toshiro's attempts to calm her down…

[Edited from Steam]