In modern Japan, the number of public baths continues to decline.Meanwhile, there were four beautiful sisters who ran a traditional public bath inherited from their parents.Their cheerful and healthy working appearance was well received by customers, and sales doubled and prospered.They have a secret that no one knows.That is, they are lesbians, and they are doing lesbian sex with sisters when they have free time while preparing to open or closing business!Approaching the secret sex of such four sisters!