After battling against Prima, Ash and co. walk through a town. They notice all of the old buildings just like a history book. A young girl comes running down looking for Maria. She asks Ash and co. to help her find Maria. She tells them that Maria is her Nidoran. She describes the Nidoran to them. Ash looks up Nidoran in his Pokédex. Nidoran Male and Nidoran Female look very different. Ash and co. agrees to help find Maria.

They search through the park for Maria. Pikachu sees some delicious berries on a tree. It walks closer to the tree as it calls out for Maria. Ash sees a boy calling out for his Pokémon, Tony. He asks Ash and co. to help him find it. Tony is a Nidoran, but it's a male. Ash looks up this Nidoran in his Pokédex. Brock and the girl runs up to them. The boy sees the girl, and he accusses her of kidnapping Tony. The two of them begin to fight. They pick up sticks and begin hitting each other with them. Marill walks up to Tracey. Tracey thinks that Marill might've found something. Thinking that it was their Nidoran, the boy and girl tramples Tracey down to find them. At the center of the park is Tony and Maria. Tony picks up a flower, and it gives it to Maria. Misty says that the Nidoran are in love. Tracey is busy sketching the two Pokémon. The boy and girl picks up their Nidoran, and they leave.

Ash and co. goes to a restaurant. They talk to the chef about their problem. The chef tells them that the boy and girl are Ralf and Emily. Everyone in town knows them. When they were little, they were always catching the same Pokémon, and they competed. Because Ralf and Emily are so stubborn, the Nidoran won't ever be together with each other. Ash and co. walk outside the restaurant. They see Tony run by. Tony runs about to Maria, and the two Pokémon talks to each other. Misty can see the feelings of the Nidoran. Misty comments on how Ash isn't mature enough and that he hasn't grown up yet. Emily sees Tony and Maria talking to each other. She throws a bucket of water onto Tony. Ralf runs up to Tony and brings him inside the house. Ash and co. sees that Ralf and Emily are neighbors. Misty wants to do something about this. She calls Ash a big baby because he thinks that Pokémon is more important than love.

Team Rocket is spying on them. They dream on things that they can do with the male and female Nidoran.

At the Pokémon Center, Misty starts to write letters to Ralf and Emily. Misty plans to write the letters, and Ralf and Emily will think that both of them sent the letters. Misty thinks that Ralf and Emily really like each other. Meanwhile, Team Rocket plans to capture the Nidoran. Jessie tells a story about how she could never find someone to love. After the story, Meowth talks to the Nidoran about getting connected with each other. Meowth walks out, and he tells Jessie that the Nidoran won't come out from the house because they would be disobeying their masters.

The next day, Misty has mailed out the love letters, and the group waits behind a tree. Misty adds on that she sent Emily some flowers and Ralf got a remote-control airplane. Ralf and Emily walks up to each other. They are angry at each other for sending the letters and gifts. They start to beat each other with sticks again. Suddenly, two people walks up to them. It is a bride and groom. They are Team Rocket. They snatch the two Nidoran from their trainers. A cake platform rises up as they recite their motto. The cake opens up, and the balloon appears. Team Rocket jumps into the balloon, and they float away. Misty blames Ralf and Emily for this. She says, "If you hadn't been fighting, this never would've happened." Ash and Tracey observe the cans on the ground. Tracey assumes that they have dropped from Team Rocket's balloon. Now the trail of cans will lead them right to Team Rocket.

Team Rocket is trying to dress up the Nidoran for the boss. Ash and co. walks up to them, and they demand for the Nidoran back. Meowth wonders how they found them. Tracey shows Team Rocket a bag of cans. The Nidoran runs away from Team Rocket. Jessie tells Arbok to attack them, but the Nidoran use Tackle on Arbok. Victreebel is sent out next. Maria uses a Scracth attack on Victreebel, but Tony gets hurt from Arbok. Maria makes sure that Tony is okay, and together they fight Arbok and Victreebel. Ralf and Emily watches the battle. They see that the Nidoran are battling for each other. Arbok has the Nidoran caught in its Wrap attack. The Nidoran use Bite causing the Nidoran to get free. They use another Scratch attack on Arbok and Victreebel. Ralf and Emily calls out for a Fury Swipes attack, and the Nidoran scratches Team Rocket's Pokémon. Finally, a Double Kick attack causes Arbok and Victreebel to faint. The Pokémon are returned, and Team Rocket goes back into their balloon. Meowth turns on an air hose. Pikachu grabs onto a branch, and it gets sucked up to the air hose. Pikachu then uses a Thunderbolt on Team Rocket. Misty sends out Staryu. Staryu rips a hole in the balloon, and Team Rocket blasts off again.

Misty tells Ralf and Emily that they should make their Pokémon happy. Ralf and Emily doesn't know how to say goodbye to their Pokémon. Tracey suggests that Ralf and Emily should build the Nidoran a little house between their houses because they are neighbors. Now the Nidoran can be together. Suddenly, the Nidoran start to evolve. They evolve into Nidorino and Nidorina. Ash looks up both Pokémon in his Pokédex. Tracey thinks that this is a fairy tale. Tracey wonders how the Nidoran evolved. Ash asks Misty if people change when they get kissed. Misty blushes and says, "Guess we will have to find out for ourselves." Ash and co. waves goodbye at Ralf and Emily. Team Rocket is caught in the bells of a church.