Imouto no Hou ga Onee-chan Yori Kawaii Desu yo, Senpai?
妹のほうがお姉ちゃんより可愛いですよ、先輩？
A boy confesses his feelings to Ayahi, the girl he is interested in, but the attempt fails due to interference from her younger sister, Azuki. As an apology, Azuki offers to allow the boy to do with her what he had intended with her sister. This leads to Azuki increasing her teasing behavior toward him.