Out in the open seas, Sun cries out in bewilderment when he realizes that he is currently sailing off on a yacht-boat towards the endless horizon. However, a voice comes on to silence him, and he turns around to discover that Moon is actually on board with him. The girl is apparently focused on aiming her bow and arrow at something, and he gazes out from the back of the deck to see that the two Team Skull Grunts are chasing after them on a small rubber boat. Yet, something else hovers just slightly in front of the rubber boat, and he soon realizes that it is Rowlet and the poor little Pokemon is being assaulted by the Grunts' Salandit and Pyukumuku.

Before Sun could react, Moon releases her grip, and an arrow flies straight towards Rowlet. A green Berry on the arrow tip lands directly into the beak of Rowlet and as it swallows the Berry, its speed tremendously increases, allowing it to easily out-speed the rubber boat and reach the yacht-boat in an instant. Grunt A gawks in disbelief and fails to understand what has happened, and the female Grunt cries in annoyance that Rowlet has been given a Salac Berry to raise its speed in a pinch.

On the yacht-boat, Moon catches Rowlet as it snuggles up to her, and Moon explains to Sun that it has apparently been ambushed by Team Skull after it saw them off at the Hau'oli Marina. At the moment, Prof. Kukui emerges from the steering room, and thanks Moon for saving Rowlet. He notices how acquainted it is with Moon, and postulates that it wasn't really seeing her off but probably wanted to come along. He suggests she add it to her team, and Moon gladly accepts that offer.

Watching Moon and Kukui interact while leaving him ignored, Sun throws a fit and demands that someone explain to him what is going on. Kukui only then realizes that Sun has regained consciousness, and makes a joke that he didn't come around to notice that Sun has come around, which causes the boy to cringe. Kukui decides that it is indeed time for some explanation, and wants to know if Sun remembers how he passed out after winning the Z Battle Tournament the night before. Sun replies with a nod, and before Kukui could say anything else, Moon cries out that the yacht-boat is going astray. Kukui realizes that he has left the steering wheel, and Sun collapses at the man's absurdity.

With his hands back on the steering wheel, Kukui states that everyone including the Kahunas, Samson Oak and even himself believed that Gladion would emerge victorious in the final match. Sun gets upset at the comment, but Moon simply rolls her eyes and Kukui reminds him how Litten's peculiarly powerful move secured him his victory at the end. Sun recalls the abnormally strong 'Ember' attack, and Kukui remarks that the Kahunas believed the move was activated by the powers of the 'stone' Sun used as a splint. Kukui wants to know how Sun came to possess the 'stone', and Sun reveals that he picked it up from the ground. His answer astonishes both Kukui and Hala, who just made contact with them via video-conferencing. Kukui greets Hala warmly, and the Melemele Kahuna starts off by congratulating Sun on his victory at the Z Battle Tournament. He wants to know how Sun is feeling, and the boy replies that he seems to be doing well. Hala voices out his worry that Sun passed out because his body could not handle the tremendous amount of energy channeling through his body, but Sun apparently has no idea what the old man was talking about.

Hala decides to get back on the topic of the 'stone', and wants to know what the boy meant by picking it up from the ground. Sun says it is a literal description and recalls how the Pokemon called Tapu Koko dropped it on the ground after they fought. Kukui squints his eyes and thinks Sun must be planning on exchanging the item for money, but Sun feels offended by the remark, and states that he has been meaning to return the lost item to Tapu Koko. He finds it insulting that Kukui would suggest he sell off other people's things without asking simply because he is in need of saving money, and Kukui quickly apologizes. The man declares that he is making no such implication, and after a making a disgruntled sound, Sun decides to let it go.

Hala contemplates on Sun's explanation with how Tapu Koko left the item after a battle, and comes to the conclusion that it must be an item the Tapu bestowed upon Sun. Sun bolts in astonishment that Tapu Koko actually gave him the item, and in this case thinks it should be alright that he sell it off along with the Island Challenge Amulet. He starts to fish through his pocket for the stone but to no avail, and Hala reveals that the item is currently with him. He explains that the stone is properly known as the 'Sparkling Stone', which he is in the process of polishing. The fact that he not only won the Z Battle Tournament but was also bestowed upon the Sparkling Stone from the Tapu shows that Sun is no doubt the person to take up the mission.

Sun feels baffled by the term 'mission', and Hala reveals that an impending crisis is threatening the region of Alola. In response to this, the Tapus are enraged, and it is necessary that someone voyages across the four islands of Alola to connect with the Tapus in order to face the crisis. He explains that this is what the top prize of the Z Battle Tournament, the Island Challenge Amulet symbolizes, as it is the ornament meant to be worn by the person who takes up this great mission.

Hearing Hala's explanation, Sun goes berserk, and frantically claws at the screen, causing Moon and Kukui to hold him back. The boy hollers that this sounds more like a punishment rather than a reward that prizes are supposed to be, and seethes that he has no time to bother about any crisis when he is busy saving 100 million yen. Hala grins that he has anticipated his reaction, and thus decided that rather than being a 'mission', he is treating this as a 'job request' on Sun's courier. In order to pacify the Tapus' anger, they will need the Mirage Berry, and he shall be asking Sun to help him deliver these Berries as a 'job request', which will naturally have rewards as well as financial coverage for expenses during the delivery.

While Hala's words put a look of shock on Sun's face, it doesn't last for long and in the next instant, Sun beams with confidence and accepts the offer, which causes Moon to raise her eyebrow with an 'I'm not surprised' expression. Before Hala cuts off the call, he promises to make contact again when he has finished polishing the 'stone', and tells Sun to get the delivery slips from Kukui. Sun realizes with black lines on his face that Hala and Kukui anticipated this conversation exchange right from the start, and while Kukui makes no attempt to deny it, Moon snickers that she would have made the same guess even having known Sun for a mere 3 days.

Sun goes through the delivery slips to see the different Tapus he is supposed to deliver the Mirage Berry to, and wonders what exactly it is. However, before he gets an explanation, the mysterious talking red machine shows up again to inform them that Akala Island is near. Sun quickly bolts up, and demands to know what the creature is. The machine displays astonishment since they have already met the day before, and when Kukui reveals that it is the Rotom Moon brought to him, Sun realizes that it has finally entered the Pokedex. The boy feels grateful that a talking Dex will make his work much more convenient, but to his shock, Rotom-Dex backs away and Kukui suggests he clarifies whose Pokedex it is first. Moon reveals that Prof. Kukui actually possesses an extra Pokedex and has given it to her upon request. That said, Rotom has actually entered the Pokedex of Moon, but not the dirty and damaged one Sun owned. Speaking with a tone of mockery, Rotom-Dex stuffs Sun's Pokedex back to him, and tells him to take good care of it, much to the boy's annoyance. Soon, the silhouette of an island with a huge volcano comes into view, and Kukui announces that it is time to embark on Akala Island.

Meanwhile, at Melemele Island's Ruins of Conflict, Gladion walks towards the altar with his Type: Null. To his surprise, someone is already present and expecting him, and it is no other than Guzma, the leader of Team Skull. Guzma wonders if Gladion flew over since the suspension bridge has been destroyed, and informs him that Tapu Koko doesn't appear to be around. The man straightens himself up to face Gladion, stating that he has been looking for him, but the boy remains silent and simply stares back at him emotionlessly. Guzma giggles that he doesn't have to appear so hostile, as they were fellow contestants in the Z Battle Tournament just a while ago. He even points out the fact that Gladion didn't send out his second Pokemon in the finals and let the courier boy win, and Gladion wants to know what he wants from him.

Guzma relents that Gladion surely is a cold kid, and decides to cut it to the chase and voices out his desire to hire him as a bodyguard of Team Skull. He admits to have been impressed by Gladion's skills at the festival tournament, and while his members do have style, they could really use some work and he intends to recruit someone strong to straighten them out. While Guzma intends to elaborate further, Gladion simply accepts the offer, and the Team Skull Boss is a bit taken aback by the boy's directness. Gladion wishes to know one thing, however, and recalls what the man said about 'only answering to one person' when he left the stage. He wants to know if Guzma has another boss above him, but the man simply smirks and says he doesn't remember saying such a thing. He beckons Gladion to follow him instead, and decides to show him the hideout of Team Skull.

Back at the Ferry Terminal of Akala Island, Sun and Moon wait at the port, and Sun is starting to get impatient that Prof. Kukui still has not returned after the hour he anticipated. Moon recalls the professor saying that he would be going to the Dimensional Research Lab of his wife Prof. Burnet, and wonders if it is far away. Rotom-Dex replies that it shouldn't take too long even on foot, and Sun grunts that the man should just come back quick after whatever business he is up to.

At that moment, a group of three people approaches Sun and Moon, and wants to know if they are the trainers in possession of the Island Challenge Amulet. Sun admits to be the case, but is curious as to who the strangers are. His question astonishes the girl with long green hair in the group, and another girl with short blue hair postulates that they must not be from Alola originally. Sun grins that she made a right guess since he was actually born and raised in Kanto, and Moon is a bit surprised by the revelation. The three people introduce themselves at the Trial Captains of Akala Island, the green haired girl being Mallow, the blue haired girl Lana, and the dark skinned red haired boy Kiawe.

Moon requests to know what Trial Captains are, and Mallow explains that they are people who guide and test the skills of trainers with the Island Challenge Amulet. Sun thinks they sound like what would be Gymleaders in Kanto, and suddenly realizes that they are here to battle him. Kiawe is glad that Sun is astute enough to sense that, and proceeds to send out a Marowak, who quickly begins encircling the boy with its bone. Sun gasps that he didn't hear any of this from Hala, and Kiawe reveals that Trials Captains have the right to initiate their challenge. He states that it has been years since anyone took on the Island Challenge, and they are all concerned about what kind of chosen trainer they have. While they fully respect the decision of the Island Kahunas, including Hala, Nanu, and their very own Olivia, who have given their recognition at the Z Battle Tournament, they as Trial Captains must still verify whether the person who emerged victorious in a match of six could really take up on the great mission of the Island Challenge. That said, he demands that Sun prove his strength to him before he proceeds any further, and Sun realizes that he doesn't really have a choice.

Throwing out a Pokeball, Sun calls forward Dollar, and the Alolan Meowth adeptly deflects Marowak's bone strikes with its claws. Kiawe is impressed with its swiftness, and commands a Flame Wheel, which Marowak unleashes by rubbing its bone on its forehead to light it up like a match before it spinning it around. Dollar quickly ducks backwards from the flames, and Moon sees that this Marowak is probably another regional variant. She wonders if it is no longer of the Ground type since its flames are blue, and Lana, overhearing Moon's words, realizes that the girl also hails from a foreign region. Hearing that, Kiawe gets somewhat upset since the Island Challenge mission has been bestowed upon a duo of foreigners, and begins angrily spinning his own staff to create a flame wheel.

Kiawe's Alolan Marowak swings its bone to shoot out a ball of flames towards Dollar, who along with Sun, are bewildered that the flame can apparently chase after them. Lana explains to that the bone Marowak holds is from its dead mother, and it is said that its mother's sentiments have turned into the flames that guard Marowak. Rotom-Dex confirms what Lana has said, and reveals to Moon that Alolan Marowaks are of the Fire and Ghost type.

At that moment, Marowak delivers a Shadow Bone, and hits Dollar hard on its chin. Sun grunts that Marowak is using its flames to mess up its opponent's footwork before striking them with its bone, and voices out his encouragement to Dollar, reminding it that money is at stake for the current battle. Kiawe wonders what Sun meant, and Sun reveals that he is actually providing courier service on this Island Challenge business by accepting Hala's delivery request, which is why every match he participates is charged and he will lose a big sum of money if he loses. Hearing that, Mallow gasps in disbelief, and feels upset that Sun pays no respect to Alola's tradition by treating the Island Challenge as a means to earn money. However, Sun disagrees, and states that he will complete every task on the Island Challenge wholeheartedly. Tradition or not, it is a job bestowed upon his courier, which he will finish with sincerity. That said, he sees no problem with getting a reward for his work.

The words 'work' and 'sincerity' apparently remind Kiawe of something important, and the Trial Captain pauses in his tracks as Sun tells Dollar not to fear the flames so as to dodge the bone. Marowak fires off another ball of flames towards Dollar, and though the Alolan Meowth turns to run from it once more, it keeps an eye on Marowak. When Marowak attempts to ambush it with its bone this time, Dollar spins around to smacks it hard with a Feint Attack on the forehead. Moon gasps that Sun has succeeded, and Mallow face-palms that Marowak has been hit. Kiawe starts to speak with a trembled voice, but instead of saying something related to the battle, he cries out in disbelief that his boss is going to lay him off, causing everyone to collapse. It turns out that Kiawe is speaking on his mobile phone, and is making a desperate attempt to explain to his boss the emergency that made him absent from work. He apologizes for contacting his boss so late and begs him not to fire him, and eventually seems to succeed in his persuasion.

Moon wants to know what is going on, and Lana explains that Kiawe is actually working part-time at the supermarket known as the Thrifty Megamart. Mallow states that he is saving money to go abroad and further study his fire dancing, and Sun immediately reacts upon hearing the term 'saving money'. He believes that this makes him and Kiawe the perfect companions, and clasps hands with the Trial Captain, who clearly feels the same and even thanks the boy for helping him keep his job by inadvertently reminding him of it. Kiawe thinks he ought to get back now, and Mallow angrily asks what becomes of their match. Sun grins that it doesn't really matter since he was planning on using Assurance next, and Kiawe laughs that he would have been utterly defeated in that case. Black lines run down Mallow's face and the two boys give each other friendly claps on the shoulder, and Moon wonders if this means Kiawe has recognized Sun as the bearer of the Amulet, whom she still refers to as Mr. Courier. Kiawe admits with a nod, and states that one who works to save money cannot be a bad guy.

At that moment, Lana speaks up, and states that it is not alright with her. With all eyes on her, she wears a sheepish look, and says while it is already acceptable to Kiawe, Sun still hasn't earned her recognition. That said, she requests that he come with her next to the location named Brooklet Hill…