Abunai Natsuyasumi

Mio is a girl who has come to visit her relatives who live out in the countryside. Because there's not much to do, she goes out to take a swim in the river.

Though she feels embarrassed about it at first, she decides to swim naked because the environment feels so open and free.
Imagine her surprise when she notices the watching eyes in the bushes.
She ends up being punished for what she did.
Though she is ashamed as she is taken to various places wearing nothing, Mio gets aroused because of it.
Then she is taken to a mountain cabin and sexually abused. But Mio starts to feel pleasure from that too.
Even after she loses consciousness her captor continues to use her body.
This is a slightly hardcore adventure games with a branching storyline.

[from DLsite English]