A 26-year-old Chinese man was given 18 years' imprisonment for stabbing to death another Chinese man on March 9, 2009, in Chiba Prefecture. Lay judges took part in his trial in Utsunomiya District Court. In an appellate trial before Tokyo High Court, his defense counsel challenged the constitutionality of the lay judge system. On April 22 the high court upheld its constitutionality in the first such ruling.

The ruling should not be taken as meaning that every aspect of the lay judge system's operation should be accepted as is. The government and the judiciary should make incessant efforts to improve the system and make it truly reliable.

The defense counsel insisted that the Constitution did not anticipate the introduction of lay judges and that the lay judge system infringes on a defendant's right to access the courts. It said that with its guarantee of judges' official power and status, the Constitution presupposes that only legal professionals will serve as judges. The high court ruled that since the Constitution does not explicitly say what kind of people should serve as judges in lower courts, it does not exclude the use of lay judges, introduced in May 2009.