I am going to travel to Japan. What are the voltage and plugs in Japan? Do I need a transformer and plug converter to use various domestic electronic products?

Look at the power supply of your electrical appliance, such as a laptop. The adapter is the square box on the power cord. There will be a written voltage, which is usually 100V~240V.

The voltage in China is 220V, and in Japan it is 110V, so it can be used directly as long as the applicable voltage range includes 110V. If this is not applicable, a transformer will be required.

In addition, the power sockets in Japan are all two-pronged, not three-pronged. It is recommended to bring a wiring board (two-pronged plug, there are several two-pronged and three-pronged plugs on the board)