Haja serves as a recurring rival in the "Battle B-Daman: Fire Spirits!" season. His initial appearance involves attempting to steal the Drive Shot Strike Shot from Yamato Delgado immediately after Yamato wins it, triggering a confrontation where Haja deploys his Gill Scorpion B-Daman against Yamato's Cobalt Saber Fire. This act establishes him as an antagonistic figure willing to use deception to acquire powerful items.

He further demonstrates his role by directly challenging Gray Michael Vincent for ownership of the Speed Shot Strike Shot, confirming his persistence as a competitor seeking advantage through battle. Haja actively participates in multiple structured tournaments, including a B-Da golf battle alongside Aqulas, Jinbee, Wen, Liena, and Castillo, and contends in the Battle Pyramid tournament against Aqulas, Enjyu, Wen, and Kiba to qualify for the semi-finals.

A significant confrontation occurs when Terry McScotty challenges Haja to a specialized "spider match" battle on a suspended rope arena. During this encounter, Terry acknowledges Haja's prior victory over a character named Joe, highlighting Haja's capability as a skilled and tactical B-DaPlayer. Terry employs a new B-Daman and Strike Shot specifically for this rematch, underscoring the threat Haja represents.

Haja's known B-Daman is consistently Gill Scorpion across all his battles and appearances. Visual depictions frequently place him alongside this specific B-Daman.

Information regarding Haja's origins, background, personal motivations beyond obtaining Strike Shots, character development outside competitive battles, or his presence in other seasons, movies, OVAs, or spin-offs outside the "Fire Spirits!" season is not available.