Read manga: Ben-to Zero: Road to Witch

manga
Summary:

The story revolves around a poor high school student named Satou You. Satou goes to the supermarket one day and discovers a bento (boxed meal) on sale at half price. Just as he reaches to grab it, he ends up on the floor unconscious. Satou has just entered the fierce, no-holds-barred supermarket survival battle for half-price bento.
(Source: ANN)