Japanese youth justice has experienced several reforms to date. Currently, a radical revision is under consideration: to lower the age of criminal majority from 20 to 18 years. Japanese scholars and practitioners have since been engaged in debates over this proposal. Drawing on existing empirical research on youth offending and juvenile justice, the purpose of this article is to advance a critical analysis on (in)appropriateness of lowering the age of criminal majority. By focusing on its potential consequences, we also discuss what the future of youth justice in Japan would look like. We conclude with offering research implications.