You Do Need power plug adapter while traveling from New Caledonia to Tonga.

Here is Why You Need An Adapter

The outlet and plug type used in Tonga is I and in New Caledonia are C and F. This is how they look like.

In New Caledonia, outlets of type C and F are in use.

Type C

Type F

In Tonga, outlets of type I are in use.

Type I

I am from

going to