The Thrifty Megamart (Japanese: スーパー・メガやすSupermarket Megacheap), also referred to as the Abandoned Site (Japanese: 跡地Abandoned Site) is a location on Ula'ula Island in Alola, located north of Route 14. It is the location of the trial of Acerola.
The trial begins once the player enters the Thrifty Megamart; however, they can leave at any time, although this will reset the trial. If the player loses the battle against the Totem Pokémon, when they attempt the trial again the back door will remain unlocked; however, if they then leave after this, the trial will be reset. In this trial, Acerola asks the player to investigate the abandoned site using their Poké Finder to take a picture of the Totem Pokémon.
In order to lure the Totem Pokémon out, the player must take photos of several mischievous Ghost-type Pokémon. To find the Ghost-type Pokémon, the player must investigate curious phenomena in the Thrifty Megamart. When the player investigates one of these phenomena, the Ghost-type Pokémon will become visible in the Poké Finder; when the player takes a photo with the Ghost-type Pokémon in the center of the frame, it will spot the player and attack, giving the player no opportunity to submit the photos online. After defeating the Ghost-type Pokémon, what appears to be a Pikachu will run in the direction of the next phenomenon, running towards the back door once the player has defeated Gengar (the last trial Pokémon). After taking photos of the three different trial Pokémon and approaching the back door, the door will be unlocked.
In Pokémon Ultra Sun and Ultra Moon only, after defeating Gengar, what appears to be Acerola will appear in front of the back door, repeatedly telling the player to leave. If the player obeys and leaves, Acerola will be waiting outside, asking if they want to quit the trial. If the player refuses to leave enough times, an option to take a photo appears. If the player takes the photo, "Acerola" will disappear, revealing it to have been nothing but an illusion. After this, the back door will be unlocked.
After entering the back room, the Poké Finder will fire up automatically, and will be reopened automatically if the player closes it or runs out of film (preventing them from leaving without photographing the Totem Pokémon). After taking a photo of the Totem Mimikyu, the player must defeat it in battle.
In the battle with Totem Mimikyu, it will call HaunterSM/BanetteUSUM on its first turn, and call GengarSM/JellicentUSUM if its HP is below 2/3 (if the ally HaunterSM/BanetteUSUM has been defeated). If its HP drops below 2/3 before it has a chance to call an ally, it will call GengarSM/JellicentUSUM first, then call HaunterSM/BanetteUSUM at the first opportunity after GengarSM/JellicentUSUM has fainted. Once an ally is defeated, Totem Mimikyu cannot call it again.
After defeating the Totem Mimikyu, a photo of it is added to the player's Poké Finder, and they automatically leave the building. Outside, the player is greeted by Acerola for completing the trial, who checks their photo and gives them a Ghostium Z as a reward. However, she informs them that the building never had a back room despite the player encountering the Totem Pokémon there. Shortly after she leaves, a Mimikyu can be spotted walking in the background behind the fence. If the player re-enters the building, the door to the back room will have vanished without a trace.
After completing the trial, wild Pokémon will appear in the Thrifty Megamart.
The Thrifty Megamart was a supermarket built near Tapu Village. However, the site of the village and the supermarket were grounds held sacred by Tapu Bulu, causing the guardian deity to destroy everything built in the area in a fit of rage. The ruins of the supermarket became overrun by Ghost-type Pokémon, and a new Thrifty Megamart was built to Royal Avenue on Akala Island.
The insides of the ruined shop are filled with cardboard boxes and shopping carts. Some of these boxes are blocking one of the doors, leaving the right door the only way into the supermarket. A Poké Finder spot is located near the checkouts.
Thrifty Megamart appeared in A Battle Hand-Off!, where Nanu made it the trial site for Ash, knowing that Team Rocket were recently sent there by him so that they could find Ash. Upon meeting Team Rocket, Ash was surprised to learn that his trial was against them, but accepted it nonetheless. During the ensuing battle between Jessie's Mimikyu and Ash's Pikachu, Mimikyu constantly held the upper hand, until Team Rocket prepared to finish the match with their new Z-Move, Let's Snuggle Forever. The Z-Move failed to defeat Pikachu, who had unexpectedly learned Electroweb, which blocked the attack.
Immediately afterwards, Ash's Electrium Z abruptly transformed into a Pikashunium Z, allowing Ash and Pikachu to perform 10,000,000 Volt Thunderbolt to defeat Mimikyu and clear the trial. After Team Rocket was taken away by Bewear, Nanu appeared to check on Ash's trial. Upon learning of his success, he was left with no choice but to finally accept his challenge for a grand trial.
In the manga
In the Pokémon Adventures manga
The abandoned Thrifty Megamart in Pokémon Adventures
After Acerola left to do other business, Sun and Lillie entered the Thrifty Megamart, only to be surprised by the wild Pokémon that lived inside as well as a variety of objects moving all on their own. After being scared by what was nothing more than a dirty Pikachu doll, Sun discovered what appeared to be another type of Pikachu doll. The "doll" then attacked Sun, revealing its true identity as the Totem of the Thrifty Megamart: Totem Mimikyu. Sun sent out his Torracat, Dollar, to battle Mimikyu, and used Moon's Rotom Pokédex's Poké Finder function to replace the camera that was destroyed when Mimikyu revealed itself. Due to Mimikyu's speed, Sun was unable to keep up long enough to snap a picture, so he had Dollar use Inferno Overdrive in the hopes that the Z-Move's power would be able to stun Mimikyu long enough to take the shot. While the attack successfully hit, all it did was break Mimikyu's disguise, leaving the Totem itself completely unscathed. Sun realized that Mimikyu kept attacking him instead of Dollar, soon coming to the conclusion that the reason for this was because he had insulted its appearance and mistaken it for a Pikachu. This caused Mimikyu to calm down, allowing Rotom Pokédex to translate its speech, revealing how Mimikyu had made itself look like Pikachu to be liked by people. Sun then asked Mimikyu to join his team, saying that humans wouldn't learn to understand it if it just kept hiding. Mimikyu accepted the offer, and thus, after Rotom had taken a picture of Sun and Mimikyu together and emailed it to Acerola, Sun caught Mimikyu, nicknaming it "Franc". Acerola's reply came almost immediately, confirming that Sun had passed the trial.