This article explores the laws governing pre-trial detention in Japan and discusses what factors determine how long someone can be held in jail. The maximum time a person can be held in Japanese jail prior to trial is generally two years for more serious offenses and one year for less serious offenses, although these limits can be extended at the discretion of the court. Pre-trial detention can also have an impact on sentencing if an individual is found guilty at trial. Factors that determine how long someone can be held in Japanese jail include the severity of the crime, criminal history, availability of evidence, likelihood of flight risk, and availability/willingness of witnesses. Alternatives to pre-trial detention such as bail and house arrest may also be available depending on the circumstances.