Setsuya Shijo is the master of a snowbound, secluded mansion where time stood still. Numerous beautiful women serve within its walls, each devotedly idolizing and worshipping him. He is kind-hearted, the opposite of his physically identical, malevolent twin brother, Itsuya. Itsuya, previously imprisoned in the mansion's basement, orchestrated a switch with Setsuya.

After the switch, Itsuya restarts the mansion's flow of time. Setsuya finds himself bound and confined within the basement, trapped in the role his brother once occupied. From this prison, he is a helpless witness to events unfolding above, unable to intervene or assist the staff. He observes Itsuya mistreating the women, who only gradually realize an impostor has replaced their true master.

The situation escalates as a large, chained grandfather clock approaches its looming thirteenth strike. When the clock completes all thirteen chimes, one person within the mansion will permanently vanish. Throughout these events, imprisoned Setsuya remains unable to satisfy his own emotional or physical needs, including his deep concern for the staff and his personal anguish.