Kaizō began as a standard spherical Goha Corporation drone, sporting a green body and a blue display screen for a face. Yuga Ohdo extensively overhauled this unit, granting it unique sentience and free will distinct from other corporate drones. The name "Kaizō," meaning "remodeling" in Japanese, directly references this transformation and was spontaneously chosen by Yuga, though Kaizō itself found the name overly literal.

Post-modification, Kaizō's appearance gained distinctive features: a red top resembling a bottle cap with attached gold tubing, alongside blue cylindrical appendages featuring white rims. Yellow plating appeared on its left appendage, further setting it apart. Kaizō developed a personality marked by strong autonomy and occasional unpredictability. This included an intense celebrity obsession with Romin Kassidy, leading it to prioritize her interests over Yuga's commands during duels and even request her autograph. It also exhibited womanizing tendencies, openly flirting with females like Nico from the newspaper club and suggesting Romin wear glasses. Kaizō frequently displayed apprehension toward Yuga, fearing potential resets or reprogramming as punishment.

Within the series, Kaizō participated in significant duels. It defeated three Goha drones in episode 14, though an unknown external force briefly overtook its personality data during the fight. Later, in episode 47, under corporate control and using a LIGHT Machine-themed "Business Deck," it dueled but lost to Lucidien "Luke" Kallister. Kaizō often appeared in comedic or supportive background roles, such as operating fans with biased dedication to cool Romin while neglecting others, being physically restrained by Yuga due to inappropriate advances, and obsessively generating social media engagement for Rush Duel promotions.