The man Koharu loved wasn’t cheating on her…he was cheating on his wife with her! And not only that…he was the third guy in a row to do so. Dejected, she leaves Tokyo for her hometown, and rejects a future of love and marriage for a simpler life. But things have changed—her parents are struggling, the café they ran is closed, and a creepy man keeps following her around. She thinks this may be it for her, until she learns that her hometown has allowed polygamous marriage, and she’s in that man’s sights as his third wife!
In Japan's only city where harem marriage is legal, Koharu just signed up to be wife number three to local pervert and low-key sadist, Ryunosuke Date. One night, unable to stand the cries of passion coming from her next-door neighbors, Koharu bursts out of the house and encounters wife number two, Madoka. The two are having a passionate exchange of their own when Ryunosuke steps in, declaring that one of them deserves to be punished! With a pervy husband and two bullying sister-wives to live with, will Koharu ever find marital bliss?!