In Japan's only city where polygamy is legal, Koharu is now wife number three to Ryunosuke Date. When Koharu finally reaches the end of her rope in their marriage, she runs away from home—and straight into the arms of her old flame from high school! While Koharu's trying to decide whether she's having an affair or hanging out with an old friend, the Date's are enjoying their time with the sweet and innocent Urara. In fact, the whole family agrees they might like her even more than their missing wife...