You Do Need power plug adapter while traveling from Equatorial Guinea to Hong Kong.

Here is Why You Need An Adapter

The outlet and plug type used in Hong Kong is G and in Equatorial Guinea are C and E. This is how they look like.

Equatorial Guinea

In Equatorial Guinea, outlets of type C and E are in use.

Type C

Type E

Hong Kong

In Hong Kong, outlets of type G are in use.

Type G