On a normal morning in Kalos, Serena, Ash's childhood friend, walked on the streets of Route 2, intending to find a ghost-type Pokémon to train and raise it. She promised herself to meet Ash in Route 3 after capturing the said Pokémon. She adjusted her hat when she began running fast as she could, with a confident smile in her face. She greeted many people on her way with a friendly manner and told them to have a beautiful morning of Pokémon battling. Hours later, in Santalune Forest, the young female Pokémon Trainer pulled out a bottle of water after running in the route. She drank a bit as she sighed in relief.
"Well, what a nice drink of water!" She said to herself, "I promised to see Ash and tell him that I caught the ghost-type Pokémon!"
"Fennekin!" said Fennekin.
"Don't worry, Fennekin. We'll catch the ghost-type Pokémon and meet Ash on Route 3!" Serena reassured as she combed her hair, "Miette will never have a chance against me because, I'm gonna be better than her!"
"Fennekin!"
The young female Pokémon Trainer giggled as she has put her hands on her hips. However, she listened to a voice coming from the bushes, "Mismagius..." said the voice as Serena shushed Fennekin and suspected something.
"Wait a second, I guess I heard someone! Ash? Is that you?" She thought as she pulled out her Poké Ball from her backpack and walked quietly towards the bushes. She took a breath as she thought to herself, "Did Ash has sent a ghost-type Pokémon for me?" Serena was confused when she kept looking towards the bushes as Fennekin growled, preparing to attack with her moves, "I'm gonna show that Pokémon how serious I am!" She declared as she opened the bushes, only to see the Mismagius, "Mismagius!"
"Mismagius..." Mismagius replied as it approached her, "Mi..."
"You were hiding in the bushes?"
"Mismagius..."
"Fennekin!" Fennekin exclaimed with surprise.
Serena threw the Poké Ball up and down and said, "Allright, Mismagius, I don't want any trouble! But, I want you to come with me!" She aimed the Poké Ball at Mismagius. But, the Magical Pokémon stared at it and began thinking of transforming Serena into a Pokémon. It smiled mischievously and began controlling the Poké Ball with its ghostly powers, possessing it and shocking Serena, "Hey! What are you doing?! Will you just stop it?!" She ordered.
"Fennekin! Fennekin!" Fennekin pointed to the Poké Ball jumping up and down.
"What?" Serena asked before the Poké Ball captured her, leaving her hat behind as she gasped, "Mismagius! Get me out of that Poké Ball! I was supposed to capture you!"
"Mismagius!" The Mismagius snapped its fingers and began spinning the Poké Ball with the female Pokémon Trainer inside. It kept spinning, spinning, spinning until it exploded with purple smoke. Impressed by this, the Mismagius hid itself in the bushes as Serena, transformed into a Mismagius, came out of the Poké Ball, retaining her hair and blue eyes.
"Fennekin!" Fennekin tried to attack her, mistaking her for a imposter who kidnapped her trainer.
"No, no! No, Fennekin! It's me! Serena! If you don't mind, I'm gonna-"
"Okaaay! That's why I'm cute and my Pokémon will give you poison!" said a voice from a distance.
"Are you gonna give me poison? Tell me about it!" said a voice, which turned out to be Ash Ketchum.
"It's Ash!" Serena exclaimed.
Later, in the Route 3, Ash is battling with Klara, the female Pokémon Trainer from Galar and a female gym leader. They both have sent their Pokémon in order to defeat each other. Confident, Ash shouted, "Pikachu! Thunderbolt!"
"Pika!" Pikachu exclaimed as he used thunderbolt and zapped Klara's Galarian Slowbro.
"I'm gonna be cute and strong!" said Klara as she ordered her Slowbro to use Quick Draw, "Slowbro, use Quick Draw!"
She nodded as she used the Quick Draw move and moved Pikachu from the ground before using her Shell Side Arm to whack him on the face, much to Ash's shock. Along the way, Serena, in her Mismagius form, encountered Ash battling with Klara and gasped in surprise.
"Let's finish this, buddy!" He said as Pikachu used the Lightning Rod move, which zapped the Galarian Slowbro, defeating her, "Nice, Pikachu! That's good!"
"I wanted to end the battle with Quick Draw!" Klara stomped her foot on the ground.
"What? And lose to you? Klara, you almost did!"
"Hee hee! I guess you did."
"He was supposed to see me and find out how I look like," Serena stated and glared at Klara, "I'm gonna make that girl stay away from him, right now."
"Well, Ash, I heard that you're going to become a Pokémon Master," said Klara.
"A Pokémon Master, Klara. 'Cause, I'm gonna be the very best like no one ever was!" Ash declared as he adjusted his hat.
"Pika, Pika!" Pikachu pointed to Serena hiding in the bushes.
"Serena didn't came yet, Pikachu. We'll wait for her and-" The boy glanced at the bushes and was surprised, "I guess she showed up."
"Ash, when are we going to have a rematch?"
"Pikachu, I think it must be...Serena!"
"Pikachu!"
"Serena, are you a Mismagius? Why the Mismagius did to you?" Ash asked as Serena glared at him, "Oh, You were transformed into a Mismagius and you're blushing!"
"We'll see!" She said as she began dragging Ash into the bushes before throwing some purple smoke at his legs.
"Ash!" Klara was terrified.
"Serena, what are you doing?! Are you insane?!" He explained as he found himself being attacked by his own female childhood friend. Suddenly, his darker blue pants fell down and began acting strangely, "My pants! Serena, stop it!"
"I guess I like your shorts," Serena remarked as he stared at Ash's white boxer shorts, "And even your pants!"
Klara pulled out a Poké ball from her pocket as she saw Ash's pants jumping on its own before throwing the Poké Ball at Serena, enraging her, "Oops!" She smiled nervously before Serena snatched her shorts, revealing her pink panties, "You can't do this to me! I'm cute and pretty!"
"Even your shorts are pretty," Serena replied as she threw purple smoke at Klara's shorts, turning it into poison.
Now left without their pants, they realized that the smoke turned their pants into Pokéslacks. Ash felt embarrassed as he tried to grab his pant, only to be shocked as it shocked his hand, "Ow! My pants are electric!" He said.
"It's great to find yourself without your pants, right?" Klara asked sarcastically, "You can train your pants and treat it as your partner, 'Kay?"
"Serena did on purpose, Klara! Look! My pants are giving a electric stomp on your shorts!"
"Pika, Pika!" said Pikachu.
"Slowbro!" said Slowbro.
"I know, Pikachu! I can't train without my pants! My mom told me to keep them on!" said Ash, "Man, if Serena wasn't here to see this, my chances-Hang on a second."
Later on, Ash and Klara has put their pants to battle each other, intending to get them back to normal and snap them out of it. He turned his cap backwards as Pikachu watched him and said, "Blue pant! I choose you!" He pointed to his pant, "You know what to do!"
"Time to go super cute, shorts!" said Klara.
The pants nodded in agreement and began using the thunderbolt to zap the shorts. The move was called the Triple Zap, and zapped the shorts three times as it could. Klara has put her finger on the Poké Ball and ordered her shorts to use the ball of poison to damage the pants. Serena winced as she saw Ash's pants being hit with poison.
"Ash, take her down!" She encouraged him.
"Okay, Serena!" Ash nodded as he ordered, "Now, blue jeans! Use giant bolt!"
The pants jumped in the air and began summoning a electric giant bolt. The said giant bolt was formed by electricity when Klara, her Slowbro and her shorts watched with awe. And then, the bolt zapped the shorts right on the face, triggering a giant electric explosion. Fennekin, who was carrying Serena's hat, showed up as she looked around for her trainer. After the explosion, the pants and the shorts are back to normal, undamaged.
"That's the great giant bolt!"
"Gosh, I think I should use the cute poison," said Klara as she picked up her shorts and has put them on, "Next time, we'll battle, 'Kay?"
After he watched her walking away, Ash looked at his boxer shorts and picked up his pants before seeing Serena, who came back to her normal form after being transformed into a Mismagius. Without a single choice, he stared at her, "How did you do that to my pants?"
"I liked them! Remember when I used your clothes?" She asked as she remembered the day how she used Ash's clothes to train her Pokémon, "The pants has fit perfectly in my image."
"Pokéslacks are so embarrassing," Ash has put his pants back on, "But, we'll have a fun battle without trouble!"