Misty

Misty (known as Kasumi in Japanese) is one of the main characters in the Pokémon anime, particularly in the original series (Indigo League through Johto).

She is the Cerulean City Gym Leader, specializing in Water-type Pokémon, and she aspires to become a true Water Pokémon Master. Misty is the youngest of four sisters (Daisy, Violet, and Lily), who run the Cerulean Gym as the glamorous "Sensational Sisters" and often look down on her as the "runt," which fuels her drive to prove herself.

She first meets Ash Ketchum in the very first episode when he "borrows" (and accidentally destroys) her bike while fleeing a flock of Spearow. She follows him to demand repayment, but ends up becoming one of his closest traveling companions alongside Brock (and later Tracey), journeying through Kanto and Johto.

Personality-wise, Misty is a classic tomboy—fiery, short-tempered, and quick to snap or hit Ash (often with her signature mallet gag in earlier episodes) when he annoys her or acts clueless. She's outspoken, competitive, and has a sharp tongue, but she's also deeply caring, loyal, and nurturing (especially evident in her motherly role toward her baby Pokémon Togepi). Over time, she mellows somewhat, becoming more level-headed while keeping her passionate and sassy edge.

Her signature Pokémon include Starmie, Staryu, Goldeen, Horsea (later evolved into Seadra), Psyduck (her comic-relief companion), Politoed, and others, reflecting her strong affinity for Water-types.

She eventually returns to Cerulean City to take over as full-time Gym Leader, though she occasionally reappears in later seasons and specials.