姉が僕の精液つきパンツをはく理由

"I love my sister. I really love her. I want to… have sex with her."

That’s the kind of straightforward desire the protagonist, a younger brother, has.
Every day, he pours his liquid lust into his sister’s panties, somehow managing to keep his sanity intact.

"It’s wrong that siblings can’t have sex…"

Then, one day, his sister—a struggling illustrator—gets an unexpected job offer.