The lay judge system, in which randomly selected ordinary citizens work with professional judges to hear and hand down rulings in criminal trials, was introduced five years ago for the purpose of reflecting the voices of ordinary citizens in the proceedings previously monopolized by legal professionals. To serve its intended purpose, further efforts are needed to make sure that the proceedings are clear and easy to follow for lay judges.

According to the Supreme Court, 66.6 percent of the 7,698 people who served as lay judges in 2013 and responded to a survey said trial proceedings were "easy to understand" — up from 58.6 percent in 2012 but still lower than the 70.9 percent when the system was first introduced in 2009.

The top court in 2012 pointed out that criminal trials still tend to focus on documentary evidence such as written records of the accused's oral statement taken during interrogation. Those kinds of old-style proceedings must make way for ones in which the judges, including lay judges, hear testimony in court and hand down judgments based on their understandings of what they've heard.