In a Grove tells a story about a death of man through seven different accounts, opening with the account of the woodcutter who has found the corpse during his work. The woodcutter reports that there was evidence for struggle, but that the man has died due to wound in his chest caused by a sword. He also adds that he has seen no weapons, only a rope and a comb.
The second testimony is told by a Buddhist priest who has been travelling at the day before the murder. He said that he has met the man during his journey accompanied by a woman on a fine maned horse. According to the priest, the man had a sword, a bow, and a black quiver.
The third account comes from a police officer, who has captured a known criminal called Tajomaru. The officer reports that the criminal suffered an injury caused by a fall from his fine maned horse. Tajomaru was also supposed to be carrying a bow and a black quiver, however, he did not have a sword.
Next to tell her story is an old woman, mother of the woman who was seen with the dead man. She reveals that the dead man was Kanazawa no Takehiro, a samurai and husband of her daughter Masago. She emphasizes that her daughter has never been intimate with anyone but her husband, and she asks the police to find her.
Following is a confession of Tajomaru, who admitted that he has met the couple and that he wanted to have sex with Masago. He did not want to kill her husband, therefore, in order to get his way, Tajomaru needed to separate them. He lured Takehiro to the grove in the forest, surprised him, tied him with a rope, and stuffed his mouth full of leaves so he could not scream. Then he returned for Masago and asked her to come with him to the forest under the pretext that Takehiro was suddenly feeling unwell. Upon the sight of her motionless husband, Masago took out a small dagger and tried to attack the criminal, however, he knocked her down. According to Tajomaru, after the rape Masago told him to kill her husband or to kill himself, because she could not live with two men 'knowing' her. She said, she would be the wife of the one who survived. Tajomaru did not want to come out as a coward, so he untied Takehiro and they had a duel. Meanwhile, Masago escaped. After Tajomaru has killed Takehiro, he admitted that he has taken his bow, quiver, sword, and a horse, but he has disposed of the sword later on.
Afterwards comes the testimony of Masago. Based on her account, Tajomaru has left after he raped her, and her husband was looking at her with hatred. She was ashamed and no longer felt the desire to live. Masago decided to kill herself, but she wanted Takehiro to die with her too. According to her, Takehiro agreed even though he could not speak because of the leaves in his mouth. Consequently, she pulled out her small dagger and stabbed him into his chest. She also cut the rope that Takehiro was tied with. Later she ran into the forest and attempted to kill herself numerous times, but each attempt was in vain. Masago concluded that she was not supposed to die.
The last account is from Takehiro, the dead man, delivered through medium. According to him, after Masago has been raped, the criminal persuaded her to go with him and become his wife. Masago agreed with this proposal, but asked Tajomaru to kill Takehiro first. As it was not Tajomaru's intention to do so, he knocked Masago down and asked her husband if he should kill the woman for her shameful behaviour. In attempt to save herself, Masago ran away. The ghost reveals that after Tajomaru untied Takehiro, Takehiro picked up Masago's dagger that was thrown on the ground and stabbed himself. He also admits that while he was dying he felt someone take out the dagger from his chest.