300 En no Otsukiai Anime Edition(2016)

One day at the supermarket, a boy (Onii-chan") meets Sugiura Manami, a petite girl looking at the snacks corner, mulling over as to which snack to buy with her limited budget. Enticed by her cuteness, the boy decides to treat her to a snack worth 300 yen, but only in exchange for something somewhat inappropriate.