|Anime debut||Yu-Gi-Oh! SEVENS episode 001: "Let's Go! Rush Duel!"|
Kaizo is a green, spherical Goha Corporation Drone with a blue screen that serves as both a display and Kaizo's face. Following its modifications by Yuga Ohdo, it has a red top that resembles a bottle cap with a gold tube at the side, and blue cylindrical appendages with white rims; the left one with some yellow plating.
Kaizo's appearance changes subtly whenever Yuga modifies it. When Yuga modifies it to detect the longing of a man, he adds a bulb to the top and give Kaizo two red dowsing rods.
Prior to its modification, Kaizo attempted to enforce the laws of Goha City on Yuga and his friends and presumably had no more personality than other Drones. Following Yuga's modifications, Kaizo became obedient to him, but not unwilling to challenge him, insulting Yuga during his Rush Duel with Romin. It shows itself to be a fan of Romin, supporting her during her Rush Duel with Yuga and claiming that they would beat Yuga into a pulp, as well as siding with RoaRomin and supporting Roa's desire to gain the rights to Rush Dueling purely because Romin sided with them. Yuga apparently considers Kaizo a failed invention because of this, much to Kaizo's dismay, though it is unclear if Yuga is being serious. Notably, while Kaizo normally calls Romin with the pronoun "-chan", the fake Kaizo uses the more affectionate and childish "-tan", an early hint to its deception.
However, after it is stripped from its body by Nail Saionji, the fragment of Kaizo that remains in the Duel Bicycle demonstrates a loyalty and willingness to Yuga and his friends not seen before, swimming out to sea after them in an attempt to warn them of the danger they are in.
Kaizo demonstrates fear when Yuga resets or modifies it, though this does not seem to have affected its personality in the manner that Yuga had intended. Yuga theorizes that Kaizo is becoming more eccentric every time he modifies it. It dislikes tasks or qualities applied to it that it feels are demeaning, although Romin praising it usually snaps it out of this.
"Kaizo" is a Japanese word meaning "remodel" or "modification", referring to Yuga remodeling Kaizo from a Goha Corporation Drone. Yuga picks this name in the spur of the moment, a name that Kaizo feels is too literal.
The Goha Corporation Drone that would become Kaizo detected Yuga Ohdo attempting to install his Rush Dueling rules into his Duel Disk in the Hologram Man's chamber, entering after Gakuto Sogetsu arrived. The Drone warned Yuga, Tatsuhisa "Luke" Kamijo, Gakuto and Romin Kirishima that they would be penalized if they did not close Yuga's Duel Disk in six minutes and sixty-six seconds, but Luke used his mysterious power to deactivate it briefly. The Drone later reactivated, resisting Luke's further attempts to deactivate it, but apparently shut down when Yuga defeated the Hologram Man in a Rush Duel. After the Duel, Yuga modified the Drone to obey him, a task that he described as easier than hacking his Duel Disk. He used the Drone to secretly livestream his Rush Duel with Luke, revealing its presence and sending it home after the Duel.
When Yuga brought Romin to the Road Laboratory, the Drone excitedly asked for her autograph. It requested a name for Yuga to address the autograph to, so Yuga came up with "Kaizo". Yuga managed to convince Romin to Rush Duel him, and Kaizo enthusiastically gave her a Duel Disk and offered to take her guitar case for her, but Romin refused. Kaizo supported Romin throughout the Duel, demeaning Yuga constantly and trying to make him go easy on Romin. Romin was able to make a comeback and push Yuga into a corner with "Prima Guitarna of the Colorful Light" and Kaizo celebrated, but Yuga was able to make his own comeback and defeat Romin. Kaizo praised Romin despite her loss, but Yuga pulled out his tools and began to reset Kaizo, despite the Drone's protests.
Yuga later used Kaizo to help film a Rush Duel promo video, modifying it to like the video several thousand times to boost its profile. After defeating Gakuto in a Duel, Yuga modified Kaizo to help stamp Gakuto's paperwork and ease his workload. Kaizo showed up out of nowhere when Luke was Dueling Bakuro Shinjitsu, expressing adoration for the bespectacled Nico and briefly scaring her away and eagerly suggesting that Romin try wearing glasses as well. Irritated by Kaizo, Romin asked Yuga to do something about Kaizo; Yuga obliged by tying Kaizo up for the remainder of the Duel.
Yuga brought Kaizo with him, Romin and Gakuto to the Tahayasty Restaurant after he heard of its impending closure. They decided to investigate the A.I. Restaurant that was out-competing it, but Yuga and Gakuto were both refused entry, so Yuga decided to disguise Kaizo as a home delivery drone. Kaizo wasn't happy with the look, but perked up after being praised by Romin and successfully gained entry into the restaurant, recording everything it saw and taking pictures with several girls there. It returned to the Tahayasty Restaurant to report its findings, stating that it would prefer the A.I. Restaurant. After being subjected to some of Yuga's unsuccessful Roads, Kaizo witnessed Menzaburo Oomori's arrival and his ordering of the Tahayasty Restaurant Owner's last bowl of ramen, though it told Menzaburo that the restaurant's closure wasn't his fault as it would have closed anyway. It watched Yuga and Menzaburo's Rush Duel over the last bowl of ramen as the shopkeeper passionately prepared it, but was shocked when Luke ate it afterwards. The restaurant became a lot more popular after the Duel, and Yuga enlisted Kaizo to help with waiting tables, much to its displeasure.
Kaizo served Yuga and his friends drinks when Yuga brought Mimi Atachi to visit the Road Laboratory, though it was dismayed when Yuga called it a failed Road due to its attachment to Romin. That night, Kaizo remained dormant in the Road Laboratory as Mimi attempted to steal Yuga's notebook, only being briefly roused after Mimi was caught in the act. Yuga brought Kaizo with him to investigate the disappearance of the Relic from the Hologram Man's chamber, but Kaizo was unable to find any clues. After their search, Luke was challenged to a Rush Duel by Yoshio Atachi, and throughout the Duel Kaizo did his best to keep him cool due to the warm temperatures. Yuga later modified Kaizo to be capable of detecting the longing of a man, believing that it would allow him and his friends to find Gossie, but Kaizo instead detected Kan's longing to find Gossie. Yuga later deactivated Kaizo after it detected his own longing to stop Kan from pursuing Gossie any further due to Yuga realizing "Gossie" was simply the product of one of his Roads.
After Romin told the boys she was leaving the Road Laboratory one night, Kaizo explained that RoaRomin had a concert that weekend and explained the band's history to Yuga and his friends, including that of Roa Kirishima, Romin's cousin. Romin gave them tickets, prompting Kaizo to asks where its ticket was. Despite not getting a ticket, Kaizo nevertheless joined Yuga, Gakuto and Luke at the concert at Seven Hells Hall, carrying the Duel Guitar that Yuga had modified for Romin. Gakuto had also brought Romin flowers, but Luke hadn't brought anything and rushed off to find something, only to scream in terror moments later. Kaizo, Yuga and Gakuto left Romin in the dressing room and went to find Luke, finding him sitting in a dark corridor and concerned for Romin's safety. Kaizo and Luke were worried to find that Romin had left her room, but the concert began before they could investigate further. Mimi joined them at the concert, taking Kaizo's spot, much to its indignation, and Roa announced his intention to Rush Duel Yuga and his friends for the rights to Rush Dueling in a three-on-three team Duel. Luke and RoaRomin's bassist, Ushiro Omaeno, Dueled first, and Kaizo and Mimi realized that he was saying his name rather than warning Luke to look behind him. Throughout the Ghost Story Duel, Kaizo was terrified by Ushiro's scary stories, winding up clutching Gakuto in fear, though Luke eventually realized Ushiro was just saying his name and defeated him, much to Kaizo's relief.
Gakuto volunteered to Duel next, and Roa revealed that Romin would be Gakuto's opponent. Kaizo was relieved that Romin was safe, and once again began supporting her over Yuga, mocking him for not knowing that Romin had been spying on them, though Yuga claimed he'd known all along. Romin was hesitant during the Duel, prompting Luke to call her an underhanded spy and tell her to hurry up, much to Kaizo's fury. Kaizo decried Gakuto when he brought Romin to 900 LP, but was surprised when Romin went into a berserk hunger and began Dueling intensely, defeating Gakuto. Kaizo cheered Romin on, flying away with her after she returned to normal. Kaizo also acted as an MC and referee during Yuga's Rush Duel with Roa, praising Roa and Romin while downplaying Getta Taira and Ushiro. During the Duel, Roa showed footage of the Hologram Man being disqualified from the 60th Goha Dueling Tournament where he used "Sevens Road Magician", which he had given to Yuga. Roa suggested the Hologram Man had been disqualified from the tournament due to creating "Sevens Road Magician" himself, an action Kaizo confirmed to be a violation. According to Goha Duel Rules, Yuga would be disqualified if he drew "Sevens Road Magician", and Kaizo monitored Yuga's hand as the Duel continued. Yuga eventually drew "Sevens Road Magician", which Kaizo confirmed to Roa. Before Kaizo could disqualify Yuga, the Relic emerged from the ground and projected the Hologram Man, who introduced himself as Otis. Kaizo insisted that this changed nothing, but was knocked down when Yoshio entered the stage with the Newspaper Club and used as a projector to show footage of Otis's disqualification, which confirmed he had been disqualified due to being a Goha employee, and Otis himself confirmed "Sevens Road Magician" was a legal card, allowing the Rush Duel to continue. Yuga eventually defeated Roa, and Kaizo switched back to his side, praising him along with the crowd. Yuga later took Kaizo to get juice for his friends after the Duel.
Yuga connected Kaizo to the Duel Bicycle and asked him to search for Luke's favorite food; Kaizo found that it was curry rice. Romin thanked Kaizo for its help, and Kaizo was so overjoyed that it raced out of the Road Laboratory. Kaizo eventually calmed down, but was then stopped by three other Goha Corporation Drones, who had detected that it was a modified drone and refused to let it pass. Kaizo transformed the Duel Bicycle into Robot Mode to intimidate the Drones, but they assumed a TO-3 combination, so Kaizo instead challenged them to a Duel.
However, as the Duel progressed, Kaizo was contacted by an unknown entity telling him to become part of it, and Kaizo tried to flee into the Duel Bicycle, but only a small part of his data was able to escape and the rest was stolen. A fake then took Kaizo's place within his body, and reactivated after a short time. The other Drones were defeated, but the fake Kaizo remained unresponsive until Yuga mentioned Romin's name and it flew off; Yuga assumed Kaizo had been temporarily drained by the Robot Mode. The fake Kaizo and Yuga headed to Roa Kirishima's apartment, where Romin was cooking for Luke, meeting Luke himself on the way and bringing him with them. Luke wasn't happy to see Romin, as he was still angry over her betrayal, and the fake Kaizo acted as if it was incensed by Luke's rudeness towards Romin. Luke then smelled the curry Romin had cooked and was moved by how good it tasted; the fake Kaizo's taste sensors confirmed its taste as well. After Luke named the curry "Dragears Curry" due to the blue color, Romin tried to add spices to simulate the powerful second attack of "Rush Dragon Dragears", but this resulted in the curry exploding directly under the fake Kaizo and flooding the apartment.
The fake Kaizo arranged to lure Yuga and his friends away from Goha City, telling them of an island where the Relic would next appear, though in truth no such island existed. It took Yuga, Romin, Luke and Gakuto to the Goha Fishing Elementary, which would not return to Goha City for a month, but feigned ignorance when the ship's captain Nanami Maguro informed the kids they were on the wrong ship. The real Kaizo took control of the Duel Bicycle and left the Road Laboratory once its battery was completely charged, transforming into Robot Mode to swim after Yuga and getting trapped in one of the Goha Fishing Elementary's nets. The remains of the Duel Bicycle provoked a Duel between Maguro and Yuga, which Yuga was able to win. After the Duel, Yuga examined the Duel Bicycle and discovered the memory of Kaizo's data being stolen. As Yuga held the fake Kaizo down and learned from Maguro that the island the fake Kaizo had lured them to didn't exist, the real Kaizo used the last of its battery to warn Yuga that the A.I. in its body was a fake, and the fake escaped back to sure upon being discovered. Fortunately, Yuga had placed a transmitter into its body due to Kaizo's tendency to run off, and they took the Duel Bicycle back to shore with them, tracking Kaizo's body to the A.I. Restaurant.
|Goha Corporation Drones||14||Win|
- NeoArkadia (March 6, 2020). "The Organization | [SEVENS] Various Pieces of Information Revealed". YGOrganization. Retrieved March 21, 2020.
- Yu-Gi-Oh! SEVENS episode 9: "Wonderful Jurassic"
- Yu-Gi-Oh! SEVENS episode 1: "Let's Go! Rush Duel!"
- Yu-Gi-Oh! SEVENS episode 3: "Romin's Secret"
- Yu-Gi-Oh! SEVENS episode 11: "No More Holding Back!"
- Yu-Gi-Oh! SEVENS episode 7: "The Transfer Student Is an Elementary Schooler?"
- Yu-Gi-Oh! SEVENS episode 5: "Luke, a Manly Battle"
- Yu-Gi-Oh! SEVENS episode 6: "I Beg Your Noodle! Ramen Duel!"
- Yu-Gi-Oh! SEVENS episode 2: "The Man Who Possesses a Demon"
- Yu-Gi-Oh! SEVENS episode 4: "Farewell, Student Council President!"
- Yu-Gi-Oh! SEVENS episode 8: "Post-Apocalypse and Napolitan"
- Yu-Gi-Oh! SEVENS episode 10: "A Terrifying Ghost Story Duel"
- Yu-Gi-Oh! SEVENS episode 12: "The Forbidden Ace"
- Yu-Gi-Oh! SEVENS episode 13: "Another King"
- Yu-Gi-Oh! SEVENS episode 14: "Romin's Kitchen"
- Yu-Gi-Oh! SEVENS episode 15: "Setting Sail! Goha Fisheries Elementary"