The government is seeking to revise the Civil Code and 24 related laws during the upcoming regular Diet session to lower the age of adulthood to 18 from the current 20. Since the change will bring considerable change to various aspects of society and affect people's lives, the government and the Diet should devote ample time to discussing the planned revisions and set aside enough time for the people to familiarize themselves with the changes. The government plans to set a notification period of at least three years and enforce the revisions in 2022.
The idea that people legally become adults when they turn 20 has defined people's thinking and behavior since the enactment of the Civil Code in the late 1890s — more than 120 years ago. The proposed amendments, for example, will enable people aged 18 or 19 to sign contracts to purchase goods and services or borrow money without parental consent. In 2009, the Legislative Council, an advisory body for the justice minister, called for lowering the age of adulthood to 18. In 2016, a revised Public Offices Election Law went into effect to lower the voting age from 20 to 18, and a proviso for the amendment said that a similar revision should be made to the Civil Code.
Under the set of revisions, the age at which women can marry will be raised from the current 16 to 18 — the same age as men. Laws banning drinking and smoking by minors and prohibiting them from buying tickets for publicly run gambling such as horse and motorboat racing will be amended to prohibit such practices by people below 20, deleting references to "minors" to avoid confusion. The minimum age at which people with gender identity disorder can ask a family court to change their legal sex will be lowered from 20 to 18.