The protagonist is a general office worker living in a city.
A lot of bad things, such as company troubles, had befallen him consistently recently.
Then, he saw something in a travel magazine, and thought that he had change to something... Thus, he planned to start a solo journey as soon as possible.

At the Onsen Ryokan, which was recommended by a woman named Rio who he met on a trip, he will meet again for the first time in over tens of years with his old friend of another old friend, Kyoshi. And thus, they hanged out and enjoy their time together with nostalgia and coziness. Afterwards, the protagonist decided to stay for 3 weeks for the summer festival as an escape from his troubles.

There are 3 women there; Kasumi, a young lady of a ryokan, the same guest Rio, local widow Michiru, He will deepen his relationships with those attractive three married female friends of his... ....

[Self amended MTL translation of synopsis from official getchu page ]