You Do Need power plug adapter while traveling from North Korea to Niger.

Here is Why You Need An Adapter

The outlet and plug type used in Niger are C, D, E and F and in North Korea is C. This is how they look like.

North Korea

In North Korea, outlets of type C are in use.

Type C

Niger

In Niger, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F