Miki debuted as a Pokémon trainer in the main anime episode "Hot Matches!", rigorously training her Skarmory for weeks in the mountains between Azalea Town and Goldenrod City. She specifically sought battles against Fire-type Pokémon to help Skarmory overcome its type disadvantage. Her intense training regimen later inspired Ash Ketchum to refine his Cyndaquil's flame control. Miki challenged both Brock and Ash, defeating Brock's Vulpix and initially overcoming Ash's Cyndaquil. After Ash adapted her methods to improve Cyndaquil, she lost their rematch. This defeat motivated her to continue her journey and challenge Johto League Gym Leaders.

In Pokémon Evolutions' seventh episode "The Show", Miki reappeared as one of Ecruteak City's Kimono Girls. During a ceremonial performance at the Ecruteak Dance Theater, she participated in reenacting the Brass Tower fire and Lugia's departure 150 years prior. Elevated on a platform with her Flareon, she directed its Heat Wave attack to depict the inferno. Miki narrated Lugia's failed attempt to extinguish the flames with wind before collapsing to symbolize the fire's eventual quenching by rain. This ritual commemorated Johto's legendary Pokémon and their history with the towers.

Her dual roles portray a trainer dedicated to disciplined growth who later embraced regional cultural traditions.