The younger brother, who works as a researcher at a pharmaceutical company, is going to Europe next month, realizing his long-held dream of conducting research overseas. Until he leaves, he is staying with his older brother and his wife at their apartment. Hana, a chaste busty wife, spends her days supporting her younger brother with a gentle smile. But one day, when she is alone with her younger brother during a break from housework, she confesses her love to him, saying, "The truth is, I've always liked you, Sister," and the wife is at a loss for words...