At night, Lillie opens her diary and begins to write about the earlier rescue of her mother Lusamine. After concluding her entry, she hugs Snowy and says she looks forward to going to the Pokémon School the next day.
At school, Pikachu is chasing Togedemaru, though he soon stops after noticing Ash staring outside. Ash reveals that he had hoped to thank Nebby for its assistance, but it suddenly disappeared before he had the opportunity to do so. As Ash tells Pikachu that he wonders where Solgaleo is, Lillie arrives and everyone surrounds her to ask questions. She reveals that her mother has made a quick recovery and thanks everyone for their efforts. Everyone is overwhelmed by Lillie's gratitude, as Kiawe reminds her that friends help each other out. Ash affirms everyone's friendship, stating that he will help out anytime. Professor Kukui overhears the conversation before entering and formally greeting the class.
Later on, Kukui and Professor Burnet walk along a beach during the sunset. The pair discuss Ash's earlier comments, and to Burnet's surprise, Kukui admits that he wished she had been there to see their faces. They soon stop walking, and Burnet notes that she and Kukui think alike before asking him if he knows what she is thinking. Kukui refuses to give up, even though he has no answer. They have some banter before Burnet points her finger at him and exclaims that she chooses him. Simultaneously, Kukui pulls out a Poké Ball. The two stare in brief silence before Kukui opens the Poké Ball to reveal a ring inside and proposes. When Burnet, taken aback by the gesture, gasps, Kukui notes that he may have known what Burnet was thinking the whole time. Kukui and Burnet return to their house and announce the news of their engagement to Ash and his Pokémon. Amazed by this, Ash and the Pokémon hug the two professors.
The next day, everyone else learns about the engagement from Ash. The girls start fantasizing about the ceremony until Ash explains that there won't be one. However, Mallow suggests the group organize a present for the couple. Lillie and Lana add that they could arrange the whole ceremony, and everyone enthusiastically agrees to plan it in secret. Later, at Aina's Kitchen, Kiawe, Lana, Lillie, and Mallow are discussing invitation design ideas when Ash and Sophocles return to report that Samson Oak agreed to officiate the ceremony. Lillie explains that Olivia had agreed to attend, while Mallow announces that has the menu for the ceremony covered, and that the wedding cake will be Alolan pancakes made by Nina.
At night, Ash walks with Pikachu along the beach, telling him that he finds it hard to believe the wedding is tomorrow. The two look at the star-filled sky, making Ash wish Nebby was with them. Suddenly, Gladion and Umbreon approach them. Ash invites Gladion to the wedding, but he replies that he has decided to take on the island challenge, having resolved to become stronger than ever after witnessing Pikachu's 10,000,000 Volt Thunderbolt. Gladion asks Ash to thank Burnet and Kukui in his name, and proceeds to leave. Ash promises that he will continue the island challenge as well, and wishes to battle Gladion another time. Gladion pauses for a moment to smile, gestures a wave, and continues on his way.
The next morning, Ash tries to wake up a reluctant Kukui, who explains that they are off from school. Ash then resorts to using Rowlet's Peck to wake him up. Afterwards, he leads Kukui upstairs to Burnet, who is dressed in a white gown and makeup, with the rest of the class standing behind her. Kukui is surprised, even moreso when he sees the beachside wedding ceremony. Burnet explains that his students had prepared the ceremony, and he smiles at that. Soon, the wedding gets underway. Samson asks for witnesses; Burnet has her Munchlax and Kukui sends out Braviary as his. Braviary's presence surprises Ash and his classmates, who haven't seen it before, and Rotom updates its data. As Kukui and Burnet walk down the aisle to the altar, Komala rings the bell and Oak announces to the guests that they have come to celebrate the union between Burnet and Kukui.
Meanwhile, Team Rocket is out for a walk and comes across the wedding. They appear uninterested, however, and quickly leave. Mareanie briefly remains behind as she daydreams of getting married to James, but her fantasy comes to an end when James calls her over.
After Oak reads a speech, Ash nervously comes forward as the ring bearer. Kukui and Burnet take the rings and place them on each other's finger. Everyone claps, as Samson pronounces them as husband and wife, and Komala rings the bell several times more. Samson tells they can now kiss, but to everyone's surprise, Munchlax jumps and kisses Samson. The wedding festivities continue, including the cutting of the cake, the first dance, and the refreshments.
During the ceremony, Faba unexpectedly apologizes to Ash and his classmates for his actions. Lusamine explains that Faba will be working under Wicke from now on. She then asks for the class's cooperation should another Ultra Beast appear in Alola. Wicke explains that the Aether Foundation has now named the Ultra Beasts and Rotom updates its system with the new information. Per Wicke's order, Faba shows the group some details on the Ultra Guardians organization, and Lusamine invites the class to join, since Ultra Beasts tend to wander through Ultra Wormholes by accident. Wicke states that the best solution to this is to capture and return the Ultra Beasts to their homes. Upon hearing this, everyone accepts the offer.
During the bouquet toss, Lillie explains that whoever catches the bouquet of flowers is supposedly the next to get married. Burnet throws her bouquet, which lands into Olivia's hands, and she screams in excitement. Everyone's attention suddenly turns to Nebby, who makes an unexpected appearance, running across the sky. The class thanks Nebby and waves to it; it gazes at them before disappearing. Burnet and Kukui reassure Ash that he will see Nebby again someday. Meanwhile, a purple being flies out of an Ultra Wormhole. As night falls, Burnet and Kukui admit that the wedding was unexpected, but are grateful for the children's efforts. Kukui says that he was moved by Burnet's words, "I choose you." Burnet giggles, and the two admit they like each other's company.