Here lies a secret too shameful to speak of, hidden within the ordinary bond of siblings. To their neighbors, they appear as a loving brother and sister, but their relationship harbors something deeply abnormal. The brother is kind to everyone, always wearing a gentle smile—but behind that facade lies a shockingly deviant nature. And the only one who knows his true self is his younger sister. She not only accepts this dark side of him, but truly loves it. This four-episode story reveals their disturbing, twisted affection, exposing the unsettling depth and eerie allure concealed within everyday life.