Rusukaina Island

Luffy remembers training with Rayleigh on Rusukaina island one piece. From one piece episode 869 this is the part where luffy is training his observation haki to pass the test of rayleigh.

He using it at Fishman Island. copyrights belong to oda and toei animation.

All 3 types of haki Observation Haki Busoshoku Haki Haoshoku Haki.