Mitsuya Saita, a 12-year-old ordinary-ranked Bottle Battler, is the childhood friend and closest companion of Cota Coga. Their bond was forged during a period of peer rejection faced by Mitsuya, where Cota’s encouragement reignited his passion for the sport. A calculating tactician in battles, Mitsuya balances meticulous strategy with occasional flashes of overconfidence during matches.

Starting with a generic Mitsuya Cider-themed Bottleman, relentless training earned him Arrowcider DX, a precision-focused control-type Bottleman. Constrained by a tight allowance, he relied on basic gear until this pivotal upgrade. An ardent Bottle Battling devotee, Mitsuya idolizes top competitor Citrus and joins Team Citrus alongside comrades Iroha and Santa. However, he staunchly rejects the team’s emotion-suppressing AI mandate, siding with Cota and allies to dismantle the dangerous agenda.

Though eliminated early by Cota in the Bottle Royale tournament, Mitsuya later aids Cota and Ryo in confronting their ultimate trials post-crisis.

Visually distinct, Mitsuya sports purple hair with pink highlights, a white beanie, black earrings, and a prized autograph-covered undershirt from legendary battlers. His vibrant outfits mirror his zeal for the sport, while childhood flashbacks highlight yellow-accented, simpler attire—symbolizing his decade-long dedication to Bottle Battling.