Yō Satō finds himself beaten up on the supermarket floor, the last thing he remembers being going to get some half-priced bento. The next day, he encounters a silver haired girl who warns him not to go to the store again. He goes again alongside another student, Hana Oshiroi, and finds himself beaten up again upon reaching for the half price bento. The next day, he decides to act more strategically and witnesses an all-out battle for the bento that gets marked half-price, which is dominated by the silver haired girl, Sen Yarizui. After the battle ends in total defeat for Yō, Sen tells him to…