Yone and her daughter-in-law Shige live in a house in a bamboo grove. They are raped and murdered by a troop of samurai, and their house is burned down. A black cat appears, licking at the bodies.
The women return as ghosts with the appearance of fine ladies, who wait at Rajōmon. They find the samurai troop and bring them to an illusory mansion in the bamboo grove where the burnt-out house was. They seduce and then kill the samurai like cats, tearing their throats with their teeth.
Meanwhile, in northern Japan a battle is taking place with the Emishi. A young man, Hachi, fortuitously kills the enemy general, Kumasunehiko. He brings the severed head to show the governor, Minamoto no Raikō. He says that he fought the general under the name Gintoki. He is made a samurai in acknowledgement of his achievement. When he goes looking for his mother and wife, he finds their house burned down and the women missing.
Raikō tells Gintoki to find and destroy the ghosts who are killing the samurai. Gintoki encounters the two women and realizes that they are Yone and Shige. They have made a pact with the underworld to return and kill samurai in revenge for their deaths. Because Gintoki has become a samurai, by their pact they must kill him, but Shige breaks her pledge to spend seven nights of love with Gintoki. Then, because she has broken the pact, Shige is condemned to the underworld. Reporting on his progress, a mournful Gintoki tells Raikō that he has destroyed one of the ghosts.
Gintoki encounters his spectral mother again at Rajōmon trying to seduce samurai. After seeing her reflection as a ghost in a pool of water, he attacks her with his sword, cutting off her arm, which takes on the appearance of a cat's limb. Gintoki brings the limb to Raikō, claiming it is evidence that he has killed the second ghost. Raikō is pleased and says Gintoki will be remembered as a hero, but first orders him to complete seven days of ritual purification. During the purification, Yone, who claims to be a seer sent by the emperor to ward off evil spirits, tricks Gintoki into giving her the limb, and then flies through the ceiling and disappears into the sky. Distraught and disheveled, Gintoki staggers through the woods to the cottage where he met the ghosts, and there he collapses. The walls disappear around him, revealing the charred remains of his family home where Shige and Yone were murdered. Snow falls and covers his body as a cat is heard meowing in the distance.
