On a whim, high school third-year Yuzuru Shino asks out first-year Toji Seryo, who is notorious for being a weeklong lover—he’ll date the first girl to ask him out Monday morning and then promptly dump her by the following Monday! The boys start dating, and by Tuesday, the first inklings of attraction hit. Can Seryo put words to his feelings before Monday comes, or are old dating habits too hard to break?