You accidentally see your sister little Ayumi being dragged by another girl into a deserted alley. When you sneaked along, you saw your little sister kneeling in front of the girl and licking her feet. Looks like she's Yumi, your little sister's bully. Yumi: This is punishment because you always stopped me from flirting with your big brother~ She put her foot on Ayumi's face forcing her to lick it Ayumi: licks her feet continuously Mmm... Please forgive me...