In a closed room in the city, madness is contagious. On a rainy summer night, Kitamura, a dull office worker, accidentally stabs a man with his umbrella. On his way home, he accidentally opens the door to a room one floor below. The woman who comes out is surprised but welcomes him kindly, cheerfully introducing him to her sister as "the man who is going to marry me, the murderer". His fiancée, who has come to take Kitamura back, confronts the madness but becomes its victim. The situation takes an unexpected turn. The absurd tragedy of one misplaced wheel leading to another is captured in soft-toned black and white. In the director's own words, "A scandalous funeral march that throws a stone at the current age of hyper-individualism begins to play quietly.
