Benio Tsunemori, a high school girl who believes that the best thing to do is to live diligently and steadily, is the next head of the Tsunemori yakuza clan. She and her rival Watanuki clan have never been able to settle their turf war, and they have been on a parallel track. Then one day, in order to really pit the two gangs against each other, she decides to play a certain game with Nayuta, a childhood friend and incoming head of the Watanuki clan. It is a "honey trap game" in which the one who makes the other fall in love with him and make him say, "I'm so happy," wins. The story depicts how the stiff and serious Benio is swept away by the sweet words and actions of the aloof Nayuta.