Ash and his friends arrive in a small town by sunset and attempt to find a Pokémon Center. The group spots a local woman, but Brock develops a crush on her and overwhelms her with his dinner reservation offer. Misty quickly pulls Brock away. The woman admits that the nearest Pokémon Center is ten miles away, and as it is getting late the group decides to camp out in a local park. As Brock fills up a pot with water, a Nidorina rushes over to the same fountain for a drink. A frantic girl follows after it, though she trips and begins to fall. Brock, however, catches her before she falls in, causing her to fall in love with him instantly. Brock is confused and intimidated by the stranger's sudden affection. Temacu goes on to explain that her name comes from a combination of Teddiursa, Mareep and Cubone. She gives Brock his own combination name to capture his personality; "Exeggbracloy" from Exeggcute, Abra and Cloyster. Temacu admits that she is more than happy to take Brock's last name and goes on to fantasize about their future wedding. Ash is surprised by Temacu's affection. Misty then says 'You and I will be married someday, too'. Ash first replies by nodding in agreement, and then a few seconds later, after registering what she has said, yells, "Huh!!?". Temacu's father arrives at the park to collect his daughter, and at her request Brock and his friends are invited to stay over. Temacu grabs Brock by the hand and runs ahead with him.
Temacu takes them for a walk around her house, talking about her Nidorina, Nidorino, and some of the family's other Pokémon. Later, Temacu cooks dinner for the group, and afterwards they venture out onto her balcony for tea. Misty notices Brock’s discomfort, and she asks him how it feels for once. She goes on to inform Temacu that Brock can do most domestic duties, and this only impresses Temacu more. Misty pulls Brock away to have a little talk with him. She finds out that Brock has no actual dating experience and has no idea what to do. Misty is rather blunt with Brock and clarifies that Temacu is the only girl that actually likes Brock, declaring it his last chance in love. This frightens Brock, but he accepts Misty's advice.
The following day, Temacu's father shows the group more of his laboratory's grounds, admitting has plans to expand his capacity to 100 Pokémon. Temacu suggests Brock could be her father's new assistant, though Brock is unsure of the idea. Misty takes Brock aside, but Brock admits that it would be better if both people liked each other. As Misty scolds Brock, Temacu appears behind him with yet another token of her affection. She presents him with his own Nidorino that would make the perfect partner for her own Nidorina. As the pair of Pokémon cuddle up to each other, Temacu is romantically inspired and leans closer to Brock.
Just then, Team Rocket arrives and captures Nidorina, Nidorino, Pikachu, and the other Pokémon in nets. Jessie sends out her Arbok, but it is quickly sent flying backwards by a Water Gun from Ash's Totodile. James is keen for escape, so he orders out Weezing to use Smokescreen. Everyone tries to find the missing Pokémon. As Team Rocket pull in their nets, Temacu trips over the connected rope and falls. Misty calls on her Poliwhirl's assistance. It uses Bubble to get rid of the smoke. Surprisingly, the stolen Pokémon are there, but Temacu and Team Rocket are gone. Meanwhile, Jessie and James land some distance away and then realize they actually kidnapped Temacu. Temacu loses her balance, but James catches her in time. This causes Temacu to fall in love with James the same way she did for Brock. She gives James the nickname "Madewvusu", a combination of Magikarp, Dewgong, Vulpix, and Sudowoodo, to capture his personality. James is intimidated by her affections, giving him horrible flashbacks to his fiancé Jessebelle, and Jessie suggests abandoning her. They then realize that Temacu is a daughter of a Pokémon Professor, meaning the trio may have a chance to steal some more Pokémon.
Temacu's father sends out a search party into a nearby forest, consisting of a half-dozen people along with Ash, Misty, and Brock. Ash calls out Noctowl to do an aerial search; it soon finds Team Rocket's balloon hovering around and reports back. Meanwhile, a disguised Jessie and James return Temacu to her father, and Jessie claims the trio defeated the real kidnappers to save Temacu. Temacu's father is grateful to have his daughter returned and having been fooled by Team Rocket’s story, he welcomes them into the mansion. Jessie and Meowth then sneak off to find the Pokémon they accidentally left behind, and soon discover a room with a shelf full of Poké Balls. However, Temacu's father interrupts, telling them that Temacu cooked them a meal, which Jessie and Meowth accept. Jessie puts her loot bag down at her feet and begins to eat. James is already in the dining room, having no idea how to deal with Temacu's affection for him.
Ash spots the Rocket balloon flying overhead and has Noctowl put a hole in it, but it turns out to be a decoy. One of the searchers informs the group that Temacu is back, so they return to the mansion. Inside, they find Team Rocket dining with Temacu and her father. Brock, who by this time had started to develop feelings for Temacu, is heartbroken when he finds out that she has fallen for James instead. Misty inspects Jessie closely and removes her disguise glasses, she then exposes Team Rocket. As they prepare to flee, the loot bag of Poké Balls falls over, revealing the stolen goods. Jessie and her teammates rush outside, though Ash's group gives chase. Ash sends out Chikorita, who defeats Jessie's Arbok with a single Tackle attack. James then sends out Weezing to use Smokescreen, but Misty sends out Poliwhirl, who uses Bubble to hit it. Chikorita follows up with a Razor Leaf, sending Weezing flying backwards. As James prepares to attack, Temacu intervenes and has her Nidorina attack Poliwhirl. Misty is irritated and orders a Water Gun attack. Weezing dodges it, and as James is about to be hit, Temacu pushes him aside and takes the attack instead. Temacu falls to the ground from the force. Brock rushes over to check to she if she is alright. In the meantime, Chikorita uses Vine Whip to toss Arbok and Weezing into Jessie and James. Misty and Ash then blast them off with a combination of Poliwhirl's Water Gun and Pikachu's Thunderbolt.
As Temacu is being treated at her bedside, her father reveals that she has been obsessed with marriage ever since she attended her cousin's wedding. Brock officially declares that he now loves Temacu and wishes to be with her. Suddenly Temacu wakes up and falls in love with her doctor. Unlike Brock and James, the doctor accepts Temacu's affections straight away and instantly proposes to her. Ash and his friends leave to continue their journey, but Brock is still heartbroken. Misty's assurance instantly cheers Brock up, however, and he looks forward to the meeting the right girl somewhere.