Kim Campbell

Kim is competitive but comparatively unenthusiastic about tennis. She has spent years training with Carrol and is skilled enough to dominate the Campbelldon, yet she does not share her brother's strong attachment to the sport.

Material rewards motivate her much more strongly. When Cavi promises the twins a yacht for winning, Kim focuses on completing the tournament largely because she wants the prize.

She also tends to be more dismissive than Carrol when things go badly. After experiencing a serious defeat, she is much more willing to abandon tennis rather than interpreting the loss as a challenge to overcome.

Kim is a highly trained tennis player with years of experience. She possesses good reflexes, speed, coordination, and enough control to handle the Campbell family's heavily modified equipment.

Her primary weapon is a whip racket. Unlike a conventional tennis racket, its flexible structure allows the head to move on an extended cord, producing shots from unusual angles and increasing the difficulty of predicting her returns.

Kim and Carrol have trained together since childhood and function efficiently as a doubles team. Their coordination lets them compensate for the unwieldy nature of their specialized rackets.

The Campbelldon also gives them significant advantages unrelated to pure athletic skill. Their father manipulates playing conditions against opponents through traps, altered equipment, and other forms of interference.

Kim and Carrol enter the Campbelldon as defending champions. Their father's influence and their own skill allow them to advance comfortably through the underground tournament.

Their final opponents are Loid Forger and Fiona Frost, who compete undercover as the married pair "Twain Foney" and "Nafalia Foney."

The Campbell twins use whip rackets while Cavi's staff simultaneously interferes with the court, air quality, and equipment. Loid and Fiona adapt to each tactic, turning the match into a contest between elite spy conditioning and heavily rigged competitive tennis.

Kim ultimately discovers that even extensive preparation cannot compensate for the physical and tactical difference between them and the WISE agents.

Carrol Campbell is Kim's older twin brother and longtime doubles partner. He is considerably more invested in tennis than she is.

Cavi Campbell is Kim's father. He controls the Campbelldon and motivates his children with expensive rewards for victory.

Loid Forger competes against Kim while disguised as one half of the Foney doubles team.

Fiona Frost is the other member of the Foney team and helps defeat the Campbell twins.