In May 2004, Japan passed the Act on Criminal Trials with the Participation of Lay Judges, the saiban’in system. The act came into force on May 21, 2009.
At an advisory meeting in 2004, a court official described the preparation. The courts had already held mogi saiban, mock trials, to see what trials with lay judges would actually be like. The aim was a smooth start for a system that would take effect within five years. From the autumn of 2008, lists of candidates for lay judges were drawn up.