Miki is a trainer who appeared in "Hot Matches!" She'd been grinding in the mountains between Azalea and Goldenrod City for weeks, running her Skarmory through countless battles. Her real goal was to find Fire-type opponents—she knew Steel-type Skarmory struggled against them and wanted to work on that weakness.
When she spotted Brock, she assumed he was a trainer and immediately challenged him to use a Fire-type. Skarmory made quick work of his Vulpix, and later beat Ash's Cyndaquil too. But Ash wasn't discouraged; he figured Cyndaquil just needed better training to control its flame and eventually outmatch Skarmory.
That evening, Miki explained her training routine over dinner—it was seriously intense. Ash basically borrowed her methods and applied them to Cyndaquil, and it actually worked. The Pokémon finally started controlling its fire properly.
A rematch was inevitable. This time around, Cyndaquil had improved enough to take down Skarmory. Miki was genuinely impressed with Ash's progress, and the battle inspired her to stop just training in one spot. She decided to hit the road, challenge the Johto League Gym Leaders, and see how far she could go.
Content compiled by AnimeList.moe from publicly available sources.
