Don’t require power plug adapter while traveling from United States of America (US) USA to Japan.

Here's why you do not need an adapter

The outlet and plug type used in Japan are A and B and in United States of America (US) USA are A and B and they are compatible with each other.

United States of America (US) USA

In United States of America (US) USA, outlets of type A and B are in use.

Type A

Type B

Japan

In Japan, outlets of type A and B are in use.

Type A

Type B