Team Rocket are seen having shopping inside the mall as Jessie is very excited to take shopping which Meowth already knows they will have to carry her bags as Mareanie sees a shiny necklace which she likes it which James recognizes it is a Corsola horn pendant, but explains he cannot buy it, but saw Ashly who gave him some money to buy it and she teleported out of there as James brought the necklace and asked for it to fix his Mareanie which was done as a choker making her to be happy; though asked about the girl who James said was his boss's god-daughter making her to understand. After shopping, Jessie is glad to have gone shopping to relief her stress even James points out she bought too much stuff which Jessie claims shopping is her goal though Meowth corrects her it is to capture rare Pokémon in Alola. Suddenly, they see a wild, pink Frillish in the sea which Meowth notes it is a female one which James attempts to capture it, but Mareanie attacks it with Spike Cannon scaring her away which James scolds Mareanie for attacking Frillish making her cry.
"Um, Meowth. Why is she crying? I was just going to capture that Frillish to send to the boss." Meowth explains Mareanie is speaking that she could not let "another woman" have James with Jessie adding he can't even forgive a lady for being jealous which James apologizes to Mareanie, who hugs him on his face to poison him in affection. When James falls down, they encounter another wild Mareanie which is a different color. Meowth believes that the male Mareanie is James' Mareanie first love which he and Jessie see the resemblance between the male Mareanie and James as both are unreliable and indecisive. James is annoyed that is what he and Mareanie have in common as the male Mareanie hops to James' Mareanie who slaps it which has made Jessie become amused and asks of Meowth to translate this. Meowth, using pictures, tells a story about the two Mareanie as the female Mareanie was searching for love and one day, she got attacked by a Tentacruel. The male (odd-colored) Mareanie came to her rescue and protected the female Mareanie.
"I understand that. She must have been weak looking for a Corsola horn which is why she couldn't defend herself." Jessie said as Meowth continues as the latter was in crush with the male Mareanie for some time who referred to her as "little crybaby" as the male Mareanie blew away Tentacruel and came to the female Mareanie, who admitted she was searching for the beach for a Corsola horn which the male Mareanie promised to find one. However, days later, the female Mareanie saw the male Mareanie giving the Corsola horn to another Mareanie. Since that day, the female Mareanie never saw the male Mareanie again until today. Jessie believes the male Mareanie has no chance for winning James' Mareanie over, but Meowth overhears that Mareanie is making excuse that it just gave the Corsola horn to the Mareanie who dropped her own. It is why he found a Corsola horn for her, but the female Mareanie declines and goes to James grasping his leg in affection making her to show her Corsola horn necklace he got for her.
"How dare you deceived her with a fake?!" The male Mareanie becomes jealous and attacks James with Spike Cannon as Meowth realizes the male Mareanie believes James deceived the female one with a fake one. Suddenly, the male Mareanie evolves and James reads in his book it is a Toxapex. Toxapex grapples James' head and poisons him making James' Mareanie even more charmed by her Trainer's appearance. Regardless, Mareanie becomes angered for Toxapex's actions causing it to run away. Jessie and Meowth note James got poisoned badly and just as they go to search for the doctor, Bewear takes them back to it's den. At Bewear's den, Jessie and Meowth note James still has not recovered yet as James' Mareanie fetches some water for her Trainer. However, she overhears as James decided to let Mareanie go since Toxapex had bought her the Corsola horn even though he got her one. With evolving, James believes Toxapex is really someone that cares for Mareanie much more than he does and would make her happier.
'He can't mean that! He just can't!' That night, Ashly with Burnet, Kukui and her Pokémon are walking on the beach as she splashes in the water with Storm nearby, but Lycanroc sensed a presence, as Ash notices a Mareanie ahead. Later, everyone gazes at the sad Mareanie. Munchlax gives her a Pecha Berry to make her feel better, but Mareanie refuses. They believe that's Team Rocket's Mareanie, and plan on returning her to them while Rotom wonders what was she doing on the beach on her own as Burnet gives Mareanie a dish of Pokémon food, but she refuses to eat which Munchlax is interested in the food, but Burnet reminds her eating someone else's food isn't nice as Ashly chuckles, noting Munchlax ate much already as Mareanie looks at Ash laughing, and is reminded of James. With everyone asleep, Mareanie dreams of the good times she had with James during their journey and with the morning light shining, Mareanie wakes up and walks on the beach.
"I wish I know if he really means that." When she is walking, Mareanie gets attacked by a wild Tentacruel. She is saved at the last minute by James who kicks the Tentacruel away. Mareanie is happy to see her Trainer well again, and James hugs her, knowing they were worried about her disappearance. He tries to convince Mareanie to go back with Toxapex, who is behind to see her. He reminds her she is better off with Toxapex than she is with him. James tries to push her to go with Toxapex, but she refuses to do so. James forces to push her away to go with Toxapex telling her that she needs to be happy with it. James walks away, telling Jessie and Meowth it is better this way, since he won't be poisoned, Mareanie wouldn't be angry at him and they won't fail so much in catching Pokémon. Suddenly, Toxapex hits him with Spike Cannon. Meowth translates that Toxapex is angry at him for making Mareanie cry.
"Toxapex won't have the "little crybaby" be with James and nobody will be more happy for Mareanie than Toxapex does." Meowth explains as James looks mad at Toxapex.
"I also wants to see Mareanie happy, but if you could make her more happy than me, then I'll let her go so she'll be with you." James replied which is why Toxapex dares him to fight him and take Mareanie.
"Toxapex's words that if James wants to see Mareanie happy, then he has to stop Mareanie from crying." Meowth explains making James to look at Mareanie realizes he has no choice, but to fight Toxapex. He charges to Toxapes who unleashes Spike Cannon which James avoids. The rest cheer for James who tries to attack, but Toxapex dodges. Just as James gets his head out of the sand, Toxapex glomps him and poisons him. Much to everyone's surprise, James resists the poison claiming this is his evolution. The two eventually beat each other much to Mareanie's happiness. Afterwards, the battle ends up in a draw making the two fist bump each other for Meowth proclaims the two enemies are now friends. Mareanie became thankful to Toxapex for challenging her Trainer until a wild Tentacruel attacks them. James protects them grasping Tentacruel's tentacles and sends it blasting away. Toxapex gives the Corsola horn to James as a token for gratitude, but also to make Mareanie love him.
"NONONONONONONONONONONONONONONONO!" James runs away while being chased by Toxapex and Mareanie as Ashly wakes up to see Burnet asking her where Mareanie is.
"Mareanie is fine, so don't worry about it anymore." Burnet said as she watches Mareanie who chases James and smiles. After Toxapex got captured by Jessie to allow the three to be close to each other, Meowth wonders if that was an okay move to do which Jessie believes so for even if they survived, James wouldn't who gets hugged and poisoned by the happy Mareanie. Ashly saw Mareanie with James and was happy for her as she continues to school as she knows James care for Pokémon and she can't hate him for hurting Mareanie's feeling if they had made up and brought fifty of their Malasadas making them to be nice and fresh as Ashly plans to share them with everyone really as theirs are the best making many students to buy from them as they made a lot of money thanks to Ashly as she even let them have recipes for new ones making them to start cracking as they were tired after making a lot of Malasadas really for the students making Meowth to be thankful to Ashly as they have a lot of costumers cause of her.
"We owe her one for this really."
"Agreed." James and Jessie said as they were very tired from the many costumers they had.