A naughty kid living in the same apartment building is secretly taking pictures of Ayaka's underwear from the bottom of the stairs. To punish him, Ayaka sister can't hold back when he uses a toy on her pussy and she wets herself. The older sister's sexual desire is also ignited, and the battle between the naughty kid and the shotacon Ayaka sister continues, with Ayaka being made to cum by his fierce pistoning.