Kenny

Background
Kenny is a Pokemon Coordinator in the Sinnoh region. He's good friends with Dawn, having known each other since their early childhood. Both of them chose Piplup as their starter Pokemon.

Ash and Serena in Sinnoh Arc
Ash and Serena both traveled to the Sinnoh region shortly after confessing their love for eachother. At the airport, Serena's Pancham bumped into Kenny's Empoleon. Deciding that it would be best for the Pokemon to settle things in a battle, the two coordinators had a battle. Kenny used his experience to win the battle and the two Pokemon got along.

It turned out Kenny was going to enter the Floaroma Contest along with Serena and Dawn.

Kenny later taught Ash how to be a good boyfriend to Serena, having to point out that it would be a good idea to buy some flowers for Serena while he does the same for Dawn. At the Floaroma flower shop he bought flowers that matched the same colors as the five ribbons Dawn won on her first contest run.

The night before the Flaroma contest, Kenny, along with Barry and Dawn, had a sleepover with Ash and Serena in preparation for the contest. During a truth or dare game, Ash was dared to dress up in girl's clothing and then persuaded to enter the contest.

In the Flaroma Contest, Kenny used Breloom and his appeal was well-received by the judges to advance him to the battle rounds. In the first round, he easily defeated a coordinator named Sally, his Empoleon defeating her Sealeo. In the semi-finals, Kenny faced off against Serena. In a double-battle, Kenny used Empoleon and Machamp facing off against Serena's Altaria and Braixen. In the end, Kenny won by knocking out both Altaria and Braixen, setting up a finals bout against Dawn, the same matchup as the previous year's Floaroma Contest.

In the finals, Kenny used Alakazam and Breloom while Dawn used Buneary and Typhlosion. Dawn ended up the winner with Kenny lampshading he should stay away from the Floaroma contest as this was the second straight time she beat him in the finals. Kenny, along with Dawn and Barry go their separate ways from Ash and Serena after the contest.