Kaisoku Ane no Koukishin

Akkun finds out his older sister has a fetish for molestation; furthermore, she intends to try to get molested. Out of concern for any would-be molesters who might cross her path, Akkun tries to intervene. But instead he becomes the molester.

(Source: Team Koinaka)

Note: Published in Comic Anthurium 2017-03