The short story "In a Grove" by Ryunosuke Niihara tells of an investigation of the murder of a samurai named Takehiro, whose body is found in a grove of bamboo and cedars. The various sections of the story consist of the testimonies of a series of witnesses. According to the legal dictionary at TheLaw.com, "A credible witness is one who is competent to give evidence, and is worthy of belief." However, most of the testimonies in the story contradict one another in significant or petty details, so it is difficult to determine who is credible.
The first witness is the woodcutter who discovers the body. He reports that Takehiro was killed by a single sword-stroke and that nearby, he found a piece of rope and a comb, but nothing else. At first, his testimony appears credible, but it contradicts others who say that Takehiro was killed by a dagger, not a sword, and that the dagger should have been nearby.
The next witness is a Buddhist priest who saw Takehiro on the road, accompanied by his wife, Masago, on horseback. He says that Takehiro carried a sword, a bow, and a quiver with about twenty arrows. This testimony appears credible, except that a later testimony contradicts the amount of arrows in the quiver.
The third testimony is from a policeman who arrested a criminal named Tajomaru. At the time of the arrest, Tajomaru had fallen off a horse and was lying on a bridge. He was carrying a sword, a bow, and a quiver with seventeen arrows, and the bow and arrows match those taken from the dead man. The horse presumably is the one ridden by Masago. This man's testimony also appears credible, but some of the details do not match up with other testimonies.
The next testimony is from the mother of Masago. She identifies Takehiro as the husband of Masago. She says that Takehiro and Masago were traveling to Wasaka. Her testimony seems to be credible.
After this point, the testimonies from the main characters become more diverse from one another, so it is more difficult to establish credibility. Tajomaru speaks next, and he confesses to the murder. He says that when he first caught sight of Masago, he decided to capture her even if he had to kill Takehiro. According to his testimony, he lured Takehiro into the grove, tied him to a cedar, and gagged him with leaves. Masago at first attacked him but then, after he raped her, agreed to come away with him, but she insisted that first, he must kill Takehiro. To make it fair, he freed Takehiro, they fought with swords, and Tajomaru killed him. By this time, though, Masago had run away.
Masago, however, who testifies next, claims that after the rape, Tajomaru had left. Takehiro insisted that he and his wife, because of their shame, must take their own lives. She killed him but then was unable to kill herself.
The last testimony is supposedly by the dead man as related by a spiritual medium. For most people, this testimony would lack all credibility because of how it is given. The ghost of Takehiro claims that his wife agreed to go with the robber but first asked Tajomaru to kill her husband. Tajomaru left him alive, but then he killed himself.
We see, then, that the testimonies of the final three witnesses greatly contradict one another. As a result, none of them are credible witnesses—or, rather, their credibility is a matter of opinion to those who hear their testimonies.