Synopsis: Step-Siblings, But We're Not Blood-Related: It's Not Really Lewd As Long As There's No Penetration, Right?

Hanato has a cute and gentle step-sister named China. He harbors forbidden feelings for her and struggles with the habit of masturbating while watching her take a nap. However, one day, he accidentally stumbles upon China masturbating herself.Seizing the moment, the younger brother approaches his sister and invites her, saying, "Let's do it together..."—and the story unfolds from there.