Japan Customs and Tariff Bureau is an internal bureau of Japan's Ministry of Finance. It’s responsible for surveillance and control of exporting and importing goods, aircraft, and passengers in accordance with provisions of customs related laws & regulations.
Ministry of Economy, Trade and Industry is a ministry of Government of Japan. It has jurisdiction over broad areas, including Japan's industrial/trade policies, energy security, control of arms exports, etc. It also does certification of PSE certificate.
This guide introduces what is PSE certification. Anyone who manufactures electrical appliances for export to Japan or who intends to import and sell them from Japan must meet the technical criteria for the product and mark the PSE mark (forced certification.