You Do Need power plug adapter while traveling from South Sudan to Costa Rica.

Here is Why You Need An Adapter

The outlet and plug type used in Costa Rica are A and B and in South Sudan are C and D. This is how they look like.

South Sudan

In South Sudan, outlets of type C and D are in use.

Type C

Type D

Costa Rica

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

Type A

Type B