From Bulbapedia, the community-driven Pokémon encyclopedia.
(Japanese: サンのひいじいちゃん Sun's great-grandfather) is a character in the Pokémon Adventures manga. He dreamed of creating the Poké Pelago, but died before the events of the Sun, Moon, Ultra Sun & Ultra Moon chapter.
Sun's great-grandfather first appeared in The Grand Entrance and Delivery Boy Sun. He was shown talking to Sun in a video call and introduced him to the regional variant version of Meowth. Sun was so impressed that he wished to be able to go to Alola himself.
In PASM19, Sun revealed to Moon that the reason he needed to collect 100 million yen was to buy back an island owned by his great-grandfather that was taken by the Aether Foundation.
Later, it was revealed that when Sun arrived in Alola, he found that his great-grandfather passed away the night before he arrived. Faba, a member of the Aether Foundation, had the body be carried to a funeral home elsewhere so the island could be converted into Aether Paradise. When Sun objected to this, Faba revealed that the boy's great-grandfather received the island from a now-missing member of the Aether Foundation. With the man's passing, the Aether Foundation had chosen to take the island back. Faba halfheartedly stated that if Sun made 100 million yen, he could buy the island back.
Five years later, Sun met with Faba again. Using his Spoink piggy bank, Sun gave Faba all the money he had collected and promised that once he finished another set of jobs, he would have all the money he needed. Faba laughed at Sun's dedication, revealing that the island had already been converted into Aether Paradise, and the 100 million yen wouldn't nearly be enough to return the island back to its previous state.
|| Meowth (×3) ♂
| These Alolan Meowth are Sun's great-grandfather's only known Pokémon. They were first seen when Sun's great-grandfather tried to show them off to Sun, but their selfish personalities led to them ignoring him. One was later seen sitting next to Sun's great-grandfather's dead body just before it was moved to a funeral home.
None of their moves are known.
|| The Grand Entrance and Delivery Boy Sun