A story about a sister desperately trying to comfort her older brother after he gets dumped by his first girlfriend. Noticing how lonely he feels without a girlfriend, the sister comes up with a unique suggestion: "Onii-chan, if we do it doggystyle, you won't see my face, so you can just pretend I'm your girlfriend!" Driven by her affection for her brother, she resolves to comfort him with her own body, fully exposing her big ass to heal his heart. When she sees her brother happily reconciling with a new girlfriend, a pang of sadness tightens in her chest, pushing her to intensify her seduction. An episode deepening the bond between brother and sister.