You Do Need power plug adapter while traveling from Japan to United Arab Emirates (UAE).

Here is Why You Need An Adapter

The outlet and plug type used in United Arab Emirates (UAE) is G and in Japan are A and B. This is how they look like.

Japan

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

Type A

Type B

United Arab Emirates (UAE)

In United Arab Emirates (UAE), outlets of type G are in use.

Type G