On Wednesday, the Tokyo District Court sentenced a suspect who had claimed that a Super Saiya-jin (Super Saiyan) alien character from the Dragon Ball anime told him to stab another man with a kitchen knife. Presiding Judge Masato Itō certified that the suspect, a 38-year-old unemployed man named Mitsuru Imai, had diminished mental capacity. Therefore, the judge sentenced Imai to a three-year prison sentence, suspended for five years, for the attempted murder.

Imai claimed that he stabbed the victim because he was told "Kill with a kitchen knife" and "That man" by a Super Saiya-jin. Therefore, the defense asserted that Imai had diminished responsibility at the time of the crime as a mitigating factor. While Judge Itō ruled that Imai had diminished mental capacity, he also ruled that it was not enough to declare Imai not guilty by reason of insanity.

The judge explained that he gave Imai a five-year suspension because he hoped that Imai would continue to receive treatment, as the defendant had very little presence of mind to avoid committing the crime.

According to the case, Imai was on the street in a shopping area of Tokyo's Taitō ward on February 8, 2010. Imai thought he was being harassed by an unfamiliar man who had been drinking since morning, and then Imai bought a knife from a nearby convenience store. Imai actually stabbed another man who resembled the man he thought was harrassing him. The victim, who was 57 years old at the time, received serious stab wounds in the abdomen that took five months to heal.

The prosecution had asked for a five-year prison sentence without suspension. If Imai is not convicted of another crime in the next five years, he will not have to serve the prison sentence.