After defeating Kahuna Olivia, you should meet the Aether Foundation Chief in Hano Grand Resort, with a side trip to Hano Beach.
Explore the Beach
At Hano Grand Resort, you can go east to Hano Beach, where there is a hidden Soda Pop to the right of the upper-left beach umbrella.
There is a hidden Pearl southwest of the Swimmer who is standing on the beach.
A woman in the northeast part of the beach will give you a Soda Pop.
To the right of the woman who gave you the Soda Pop, there is a hidden Heart Scale.
You can talk to the bellhop in the eastern part of the beach to become a Pyukumuku chucker. Just go up and down the beach looking for Pyukumuku, and check on each one you find. After you get all six, talk to the bellhop to get 20000 Pokédollars.
There is a hidden Pearl behind the lifeguard tower.
In the northeast end of the beach, there is a hidden Heart Scale south of the beach umbrella.
Check on the rustling sand to encounter wild pokémon such as Sandygast and Staryu.
Surf in Hano Beach
In the southwest water of Hano Beach, you can battle Swimmer Chelsea, who has a level 26 Pyukumuku. You get 624 Pokédollars for winning.
Near Chelsea, there is an Antidote.
Northeast of that, you can battle Swimmer Roddy, who has a level 25 Gyarados. You get 600 Pokédollars for winning.
Near Roddy, there is a Dive Ball.
Northeast of Roddy, you can battle Swimmer Laura. She has a level 25 Goldeen and a level 25 Staryu. You get 600 Pokédollars for winning.
Northeast of there, in the water, you can battle Swimmer Lawrence. He has a level 25 Basculin and a level 25 Poliwhirl. You get 600 Pokédollars for winning.
On the island north of Lawrence, there are Black Glasses.
Northeast of that island, you can battle Black Belt Ross. He has a level 26 Mankey. You get 832 Pokédollars for winning.
North of that island, you can battle Swimmer Alicia. She has a level 25 Pelipper. You get 600 Pokédollars for winning.
To the north, there are splashing water spots. If you get too close, the splashing water will swim toward you, and you battle a pokémon.
North of the splashing water, there is a Pearl String underwater.
Hano Grand Resort
Before you go into the hotel, talk to the boy near the Pelipper and agree to watch the wedding. You get a Rose Incense.
There is an interviewer who is harassing a Pikachu in front of the hotel. If you step in, you battle Reporter Rita. She has a level 26 Miltank. You get 1040 Pokédollars for winning. After the battle, you receive a Pikanium Z.
In the hotel, go up and you will meet Faba. He asks if you will go for a tour of Aether Paradise. If you are ready to go, say Yes. But there are some things that you can do in the hotel lobby before you go:
In the hotel, there is a man who will teach moves to Keldeo or Meloetta.
There are a couple of Golfers bothering a Machamp on the left side of the lobby. If you try to stop them, they battle you. They are Golf Buddies Tara and Tina. They have two level 26 Oricorio. You get 3120 Pokédollars for winning. Afterward, you get TM45 Attract.
You can get Footprint Ribbons for your pokémon from the Pokémon Breeder in the lower-left part of the lobby.
In the upper-left part of the lobby, you can battle Veteran Kiara. She has a level 27 Trumbeak. You get 2376 Pokédollars for winning. Afterward, you get a Metronome.
In the upper-right part of the lobby, approach the Crabrawler, and the nearby Dancer will ask you to battle her and use a Z Move. Dancer Ronda has a level 26 Crabrawler. You get 1040 Pokédollars for winning. If you used a Z Move during the battle, Ronda gives you five Full Heals.
Now, if you are ready to move on, talk to Faba and agree to go with him to Aether Paradise. Before you go, Professor Kukui asks you to meet him in Malie Garden when you reach Ula'ula Island.
Aether Paradise
In Aether Paradise, you will meet Wicke. In the conservation area, you can explore the bottom-right part of the area, then go to the bottom-left, and from there you can go to the upper-middle part of the area to find President Lusamine.
After a cutscene, go up to the pokémon to battle it. It can attack with Venoshock. You can't use Poké Balls in the conservation area, so don't try to catch it. If you don't knock it out after a few turns, it will run away.
During the next cutscene, Wicke gives you TM29 Psychic.
After a cutscene, you will arrive in Malie City.