A non-members-only happening bar in a neighbouring prefecture, which a junior girl who goes to the same gym found out about from somewhere.
The shop is on the first and second floors of a communal building in a back alley, and the alley-side wall is entirely made of glass, so there is a good view from outside and inside.
It is famous in the neighbourhood as an anarchic swapping spot, perhaps because of the large number of accompanying customers.
While the couples' customers are mostly working people, students and other young people make up the majority of customers on the general customer side.
Note that ejaculation without a rubber is prohibited.