Yuko debuted in The Transfer Student. She, Yuki, and Maya were first seen greeting Blake as he went to class. Later, Cheren held a miniature tournament where his students battled each other in two groups separated by gender. Yuko lost, but congratulated Whitley for winning the girls' side. In Movie Panic, Yuko went on a class trip to Pokéstar Studios. After returning to school, Yuko and the other girls consulted on their plans for the upcoming cultural festival. When Hugh reminded the girls they had to return to their dorms, Yuki told him off, one of her comments angering him into attacking until Leo stopped him. Yuko and the others angrily left while telling Hugh they wanted him to get expelled.
In Choir Tournament, Yuko competed in the Autumn Choir Tournament as a member of Team Jigglypuff. The team eventually won, and as a reward for their performance, Roxie had her father take the winning team and their class to Castelia City to participate in the Unova Choir Tournament. Shortly after they arrived, Roxie found a member of the Unova Choir Tournament's executive committee injured and his Karrablast stolen by Team Plasma. Blake, Whitley, Hugh, and Roxie went to find the thieves while Yuko and the others stayed behind to look after the committee member.
In Therian Forme III, Cheren and his class gathered at Prime Pier. Yuki tried to tell Cheren about the situation, only to be interrupted by Hugh, who revealed that a member of their class is a member of Team Plasma. Hugh decided to leave school and fight Team Plasma, but was stopped by Whitley. Finding this behavior suspicious, Yuko and the others began to suspect Whitley, only to be affected by her Foongy's spores, putting them all to sleep.
In PS541, Cheren woke up to find that he, Roxie, and his class were taken to the Marine Tube. Benga, a Trainers' School student suspended for picking fights, and Marlon moved everyone to safety after Castelia was frozen by Team Plasma's flying ship, the Plasma Frigate. While Cheren and the others discussed how to deal with the threat, Yuko, Yuki, and Maya assisted N's Zorua, who disguised itself as Whitley to fool the class into thinking she never left. This successfully convinced Yuko and the others that Whitley was never a Team Plasma member.
In PS548, Yuko helped take Hugh to the Trainers' School, where she and the other classmates apologized for treating him poorly and begged him to start attending class again. Embarrassed, Hugh agreed to come back to school and apologized for his earlier behavior as well. Later, Yuko attended the Trainers' School graduation ceremony with her classmates.
| Sunkern is Yuko's only known Pokémon. It was first seen with its Trainer as she was heading off to class at the Aspertia City Trainers' School. Yuko bases her hairstyle and shirt on the leaves and patterns on her Sunkern's body.
None of Sunkern's moves are known.
|Debut||The Transfer Student|
|This Jigglypuff was partnered with Yuko during the Autumn Choir Tournament. Together, they performed in Team Jigglypuff and faced off against other students. In the finals, Team Jigglypuff faced off against Team Sawsbuck, but eventually came out on top.|
|This article is part of both Project Manga and Project CharacterDex, Bulbapedia projects that, together, aim to write comprehensive articles on the Pokémon Manga and CharacterDex, respectively.|