“Is your wife at home?” An unfamiliar woman visits the home of college professor Hirokawa just days after his wife has died of an illness. Hirokawa rushes to the door, but no one is there. Meanwhile, disquieting events beset Hirokawa’s university -- the sudden death of the Chancellor and the distribution of a suspicious anonymous document. Hirokawa had been having an affair with his wife’s younger sister Rei Mizushima, a lecturer at the same university. They were together the moment his wife passed. Feelings of guilt and an inexplicable sense of anxiety begin to torment Hirokawa.