Ryou and Zen are two men who hate to lose-especially to each other. From high school rivals to rival co-workers, these two men have always been locked in fierce competition. They've competed over grades, sports, and even the number of Valentine's chocolates received! And now that they're salesmen at the same company, their rivalry has reignited.

One night, while out for drinks, the two begin arguing about who's more experienced in love. Suddenly, their newest competition is set: the winner is whoever makes the other fall in love with them first! But will this competition of hearts really lead to a win or something far more complicated?