Han hated his wife, and he spent the night before her death wanting to kill her. As a result, he felt edgy right before the incident. Later, he realized he had worked through his anger and no longer wanted her dead, so he did it by accident.
In an unusual incident, a young Chinese juggler called Han severed his wife's carotid artery during a performance with a knife the size of a carver.
Han spent the night before the performance thinking about how he wanted to kill his wife and partner in the circus act. Han had found out that his wife had an affair, and she had killed the baby that was the product of the affair. He suspected he had killed the baby on purpose. He did not love her any more, and he was beginning to hate her.
[It] would be good if she were dead.
After he killed his wife, he felt horrified. He thought he might have done it on purpose, but he realized later that he was just fatigued because he had stayed up all night and was feeling edgy and tired right before his wife’s death, so that his control was not really there. He testified to the fact in his trial.
postolou, John L., and Martin Harry. Greenberg. "Han's Crime." Murder in Japan: Japanese Stories of Crime and Detection. New York: Dembner, 1987. N. pag. Print.