Kokoro hinako, a new character that isn't originally in pokemon ultra sun game. She often roam around melemele island and ula'ula island the most, and will offer the player to buy any of needed evolution stones including rare one in early game if she have it in stack, you find her in melemele island somewhere. she might give you tips on which area to grind exp points in the wild and ask the player silly questions, but she will NEVER appear during storyline.