Tachibana Sai was born without the capacity to feel pain in his heart — a condition that has made him efficient at quietly eliminating any threat to his sister, the one person he genuinely cares about, without drawing attention to himself. Then he meets Benio Matsuri: a young woman whose aloof, doll-like demeanor strikes him in a way nothing has before. For the first time, he feels something that resembles falling in love. The story unfolds at Maison sans Nom — an apartment building at the threshold between day and night, home to a group of young people whose lives are intertwined with the supernatural Maledicts and with each other.