A plane approaches a nightly Vermilion City. Aboard it, a man looks at the city below and tells his daughter, Regina, that she's going to be making lots of friends there. Clutching a Poké Ball, Regina mutters that she already has a friend, but says it's nothing when her father asks what she said.
The next day, Goh and Chloe head to school from the Cerise Laboratory, with a reluctant Ash being forced to come with them, as Goh is going to be giving a presentation about him. As they walk towards the school, Chloe notices Regina nearby, playing with a Glaceon she refers to as Micie. Ash and Goh call out to Chloe, and when she briefly looks at them and then turns back, Regina and Micie have already left.
At the school, Goh's presentation about Ash causes the whole class to laugh, especially when Ash tries to refute the claim that Pokémon and Pokémon battles are the only things he ever thinks about by saying that he also thinks about food. As Goh concludes his presentation, Regina and Micie enter the classroom, and the teacher introduces her as a new transfer student, who will be staying with them for a short time while her parents work in the city. Chloe volunteers to escort Regina to the Pokémon Garden behind the school so that she can leave her Pokémon there for the duration of the class. While walking to the garden, Chloe introduces herself to Regina and admits that she saw her and Micie earlier. At the park, Pikachu, Grookey, and Eevee approach Micie and try to make friends with it, much to its displeasure. Regina assures Micie she'll come see it during the lunch break and heads back inside with Chloe, with Micie looking after her.
Chloe tells Regina more about herself on their way back to the classroom, explaining how her father runs the Cerise Laboratory. Hearing the Cerise Laboratory being mentioned makes Regina recall how she overheard her parents planning to travel there to have her Glaceon examined. As soon as Chloe opens the classroom door, all the students in the room rush at her and start asking her questions. When Ash tries to calm everyone down, Micie suddenly rushes in, and, seeing its Trainer's uncomfortable predicament, launches a powerful Blizzard that freezes the entire class. Regina collapses on her knees and has a flashback to children in another school bullying her by calling her "Ice Queen" after a picture book character she resembles. Pikachu, Grookey, and Eevee, having followed Micie, break the ice and free everyone. Regina apologizes for freezing them, but Ash, Goh, and Chloe assure no harm was done, so everything is fine.
Meanwhile, at the Cerise Laboratory, Regina's parents are talking with Professor Cerise, explaining to him that their daughter's Glaceon freezes anything it dislikes, which is why Regina hasn't been able to make any friends and has been transferred from school to school. They request the Professor to examine Glaceon, fearing that separating it from Regina could be the only solution that would allow her to make friends, and they don't want her to be alone forever.
During the lunch break, other students keep their distance as Regina walks out of the classroom. Chloe tries to invite her to eat lunch with her, but Regina refuses, saying she'll be gone by tomorrow and that the teacher wants to talk with her. In the teacher's office, Regina gets so lost in thought that she doesn't even hear what the teacher is saying to her. Ash, Goh, and Chloe suddenly burst in, pleading for Regina to not be expelled and saying the Blizzard incident earlier was an accident. To their and Regina's surprise, however, the teacher wasn't intending on expelling her at all, and was just telling Regina things about the school. Chloe apologizes for having jumped to conclusions and invites Regina to have lunch with them. Regina calls out Micie, but it's still distrustful towards Ash, Goh, and Chloe. It prepares to use Blizzard again, but when Regina tells it to stop, Micie suddenly collapses on the floor.
Micie is taken to the Cerise Laboratory, where Professor Cerise performs a medical scan on it. He says that Micie is fine and just needs rest, but while Regina's good care for Micie shows, its body temperature is alarmingly low, even for a Pokémon like Glaceon. Based on what he's heard about Micie's powerful Blizzards, he deduces that it has been overexerting itself by unleashing so many of them, and could end up pushing itself to fatal levels if this keeps up. Regina tells everyone how Micie had first used a powerful Blizzard when it saved her from a group of children bullying her by calling Ice Queen. Similar incidents had kept happening, with Micie eventually resolving to constantly stay on the edge and by Regina's side to make sure no one ever bullied her. Regina starts crying and blaming herself for not having been able to protect Micie in return, like a friend should do. Chloe assures her that she and Micie are friends, and Micie protects her because it cares about her. Regina's parents arrive, having heard of what happened at the school. Regina stands up to her parents and explains to them that Micie was only trying to protect her from being bullied and ended up pushing itself too far, all because she kept hiding behind Micie. Her parents apologize for having not understood what was happening, and Regina resolves to get stronger so she can protect Micie. As Micie regains consciousness, Regina's parents are happy to realize that their daughter has had a friend all this time.
The next day, Regina meets the rest of the class out in the schoolyard and apologizes for what she and Micie did to them. In addition, she has a gift to give to everyone: she and Micie, assisted by Goh and Ash, will be creating an ice theme park for them all to play in. With the help of Micie, Arctozolt, and Dewgong's Ice moves and Dracovish's Water Gun, a snowy theme park filled with snow, an ice castle, and ice slides quickly forms in the schoolyard, and the whole class starts playing in it and having a good time. As a finishing touch, Regina has Micie use Ice Beam on the ground to form an ice rink, with Eevee assisting in the task thanks to Copycat.
Later, Chloe receives a package from Regina at the Cerise Laboratory, and opens it with Ash and Goh to find a snow globe with a miniature Micie inside it. From the accompanying letter, they learn that Micie has stopped using excessively powerful Blizzards, and that Regina is into Pokémon battles now. Regina also promises to come see them during the school break, which Chloe is happy to learn of. While Ash and Goh figure that they should battle Regina the next time they meet her, Chloe looks at the snow globe and hopes that she and Eevee can one day become as close to each other as Regina and Micie are.
