Imouto no Hajimete Kokufuku Lesson! (RJ01643004)

Big brother, will you practice having sex with me?” Hina, your innocent little sister, suddenly comes into your room in the middle of the night and proposes—of all things—a secret private lesson?! It seems she completely took to heart a crazy rumor a friend planted in her head: “Practicing being an adult beforehand is just proper manners for a girl.” She even goes so far as to say, “I’ll just look for a practice partner on an app…” No, no, no—anything but that, I absolutely have to stop her! If she’s going to get corrupted by some weird guy anyway, I might as well beat the proper way to do it into her using my fingers and that! With the “pretext” of protecting his little sister from bad guys held tight in his chest, a impure yet innocent, secret one-on-one lesson begins now—!