Knowing each other since childhood, Kazuma has always had the hots for his best friend’s younger sister, Yuuko, but has been too nervous to say anything. Being a good wingman, Naoki offers to help Kazuma put in the good word with his sister for a simple fee. Their dates are normal and sweet, but Kazuma doesn’t have the guts to even hold her hand. If he only knew how much of a submissive slut she really is—something Naoki knows all too well! Yuuko does everything and everyone her bro tells her to do, but can Kazuma finally bring a sense of normalcy back into her life?