US Name: Hau
Jp. Name: Hau (ハウ)

Details:
Hau was introduced in the Pokémon Sun & Moon trailer in May and set up as a friend of the player. It later emerged that Hau is a new trainer and he picks the Starter Pokémon that is weak to yours. He has a real weakness for malasada, a famous treat in the Alola region, and he is always in search of malasada shops. He is first battled when you get the Starter Pokémon and joins you again in the festival that commemorates Melemele Island's guardian, Tapu Koku

US Name: Professor Kukui
Jp. Name: Professor Kukui (ククイ博士)

Details:
Professor Kukui is the professor on Melemele Island and helps guide you through the various parts of the game. His area of study is on Pokémon moves to the point that he has even taken hits from Pokémon moves at times when it has furthered his research.

US Name: Lillie
Jp. Name: Lillie (リーリエ)

Details:
Lillie is Professor Kukui's assistant and is the same age as the player character. Despite assisting Professor Kukui in the study of Pokémon moves, she is not fond of making Pokémon battle, but enjoys reading. It was revealed in the Treehouse Live stream that Lillie has something living in her bag.

US Name: Hala
Jp. Name: Hala (ハラ)

Details:
Hala was introduced in the Pokémon Sun & Moon trailer in May. He initially gives you your first Pokémon at the start of the game. However, in the Nintendo Treehouse stream, it was revealed that Hala is one of the strongest trainers on Melemele Island. He runs the festival that commemorates Melemele Island's guardian, Tapu Koku