"Does it make you happy? To know you're woman number three?" In the one city in Japan where polygamous marriage (AKA: Harem Marriage) is legal, Koharu is not only getting into the swing of her four-way marriage to Ryunosuke Date—she's relishing it, too! Stormy clouds appear on the horizon, though, when Koharu's dad inexplicably appears to revoke his blessing and orders his daughter to divorce her husband and two wives. That's when the Date family springs into action to prove to Daddy Maezono and the rest of the world that they're happy as can be in this Harem Marriage!