SkunkyArt | TF-SquareSting — Gyms are for Pokemon, not people

Heather (Torga in the original Japanese version), Gym Leader of the Viavenus Town Gym and the first Gym Leader you face. She mainly works as a firefighter, especially in teaching fire safety and preventing forest fires, although she also helps her colleague Holmea fight invasive Beedrils, and the two of them grew very close as such. Her Pokémon partner is a Scorbunny. Heather specialises in Fire-Type Pokemon, and gives the Ardent Badge to the trainers who defeat her.

Holmea (Azinha in the Japanese version), the Bug-Type Gym Leader of Marsvale Town. Holmea wears a high-tech magical girl-like armor that allows her to fly around like a jetpack, which she uses it to study native Bug-type Pokemon colonies, especially those that live high up in the trees, as well as monitor their populations which have been declining due to the introduction of invasive Beedrills. She fights Beedril colonies along with Heather, and the both of them have become very close to one another. She gives the Nectar Badge to the trainers who defeat her.

Lupine (Tremor in Japanese), Gym Leader of the Montdiana Town Gym, which isn't actually within said town (despite being officially known as such). Instead, it's located within a wide outdoors area high up in the Dianine Mountains known as Silver Hollow. Lupine specializes in Ground-Type Pokémon, and he boasts of both the power of the earth to reshape the landscape around it as well as it being the sustenance of natural life itself. He gives the Landscape Badge to the trainers who defeat him.

Hawke (Rita in Japanese), the Flying-Type Gym Leader of Castelvesta Town Gym and also a historian that works to restore historical monuments. Her Gym is inside Castelvesta Fortress, an old castle whose restoration she oversaw herself. Her Pokemon partner is the regional bird. She gives the Gale Badge to the trainers who defeat her.