He was Katta's rival in the Versus season, later a distant ally in Versus Revolution and he became one of his enemies temporarily in Versus Revolution Final until he betrayed the Rare Killers. His relationship with Katta Kirifuda mirrors that of Katta's brother Shobu Kirifuda and Kyoshiro Kokujo, the only difference being that Kokujo never joined any of the main villains since he had a personal grudge against Zakira, while Kojiro joined Basara out of need for power. However, he did have a sense of conscience which resulted in him turning against Basara once his (Basara's) insanity went overboard.
He is one of the Junior High School students and Katta Kirifuda's new rival.
He has three smaller brothers who follow him around and eat his rice dishes. Kojiro is not wealthy, but he survives by being a cook. His other jobs include dueling and boxing. As a boxer, he is said to have a "hungry spirit", and the same is for him as a duelist. Katta himself noticed that he duels differently when he is "hungry". While apparently calm, during a duel he starts behaving wildly, entering "beast mode". In episode 38, his hair turns white and claws which resembles a wolf appears when he enters enhanced "beast mode". Young kids like Joe get easily frightened off by his intimidating appearance and wild personality.
Lucifer's house's location looks down on Kojiro's house, and since Lucifer is extremely wealthy, Kojiro is hostile towards Lucifer, though the feeling is not mutual. He even has a wide knowledge of Duel Masters, as he was able to explain Gyou's multicolored combination to one of his brothers. He was one of the few duelists who knew the individuals that made an impact to the Duel Masters World, such as Katta and Shobu. He also has a sense of honor and respect towards his opponents, as he gave Katta 1 point to allow him to stay in the competition.
Kojiro constantly hungers for power. This was attributed to his poor life and always tried and work hard for the sake of his younger brothers. However, because of this trait, he was unaware that he was recruited to join an evil organization, which might eventually lead to the destruction of the Duel Masters World. Despite that, he gave subtle hints to Katta about the current situation. Unlike most of the Rare Killers, he was against Basara's ambition of destroying the Duel Masters World.
He learned how to duel at a young age and won many competitions and tournaments. During one of the tournaments when he was in 6th grade, he heard from one of the audience members about Katta Kirifuda being one of the strongest duelist in the world of Duel Masters, thinking that he might be an interesting opponent. He has a fierce rivalry towards Lucifer since young and he always loses to him repeatedly during their duels.
Duel Masters Versus
He made his first appearance in episode 4. He duels Katta and shows his Dragheart card Go To Hell, Annihilator Blade / Deathshiraz, Devil Corrupt King abilities. He won against Katta and gave him a curry bread for giving a good match.
In episode 9, he duels Sasori. He accepted her duel challenge, despite looking calm, his legs are shaking, noticed by Katta. Even though Sasori managed to gain an upper hand by using her Nature Dragon combination and conducting Dragsolution, he turned the tables by using his own creatures to reduce her dragons power and conducting Dragsolution. He mercilessly defeated Sasori, but was impressed by her dueling skills, saying his wish to duel her again.
In episode 14, during the Lucifer World Cup semi-finals, his ruthless dueling skills was too much for Katta to handle and win the duel. He told Katta that he was not at the level he expected to be in. He also tells Lulu Takigawa if Katta does not become stronger, he won't be able to make it to the Duel Masters Nationals.He duels Lucifer in the finals and revealed his ability to draw cards by just punching to create a gust of wind, countering Lucifer's "transcendence pitch". But Lucifer has a counter for his method, causing him to lose the duel.
In episode 28, he tried to get the golden chopsticks for one of his smaller brothers in a ramen shop. On his way he knocked Hattori and his comrades (even Sasori and Kaeru) out of his way running to the shop only to then realize that Sasori got them first before him.
He tried to ask nervously for the chopsticks. However, Sasori was kidnapped by Hattori the dueling ninja and he rushed with Kaeru to save her. He dueled Hattori, both using their respective 3D Dragheart cards. Kojiro barely managed to win the duel,saved Sasori and he obtained the golden chopsticks from her.
He was one of the finalist in the Nationals. He watches Katta and Hokaben's live interview together with his 3 brothers by television while he was working. His first opponent in the Nationals is Sasori. Before his duel against Sasori, he gained some words of encouragement from his smaller brothers and met Hattori. However, Sasori's personality change and her ability to stir up the audience's support causes him to be pushed to the corner.Fortunately his brothers cheered for him along the way and he knew who he was fighting for.Using his renewed confidence, he defeated her and recognized her true feelings towards him. Sasori gave him a hug and he froze due to his fear of girls.
Kojiro and his brothers watched the tournament round of Hokaben and Gyou. He paid attention to Hokaben's dueling skills and was impressed by how much he had improved. He was surprised by Gyou's metamorphosis and his devilish dueling style and explained to one of his brothers on what was going on in the match. He witnessed Hokaben's endurance and his fighting spirit.
During the semi-final duel against Lucifer, he uses his punching technique, which also hits Lucifer and rips off his top,pleasing the audience. When he heard that Gyou poisoned Lucifer before their match, he was shocked by this revelation, but continued the match as Lucifer asked him to give it all he got. He defeated Lucifer by lowering Lucifer's creatures power. After the duel ends, Kojiro held Lucifer by his arms. In episode 42, he watched Katta dueling Gyou, making a slight smirk after Katta gains a comeback. He got surprised to see that Katta's brother, Shobu Kirifuda was watching the match, apparently recognizing him as one of the legendary duelists.
Before the official final match, he received a letter, in which the details shocks him.Both him and Katta have to overcome challenges before heading to the duel location; the submit of Mount Fuji. During their race, both exchanged words on reasons to be in the National Tournament. Kojiro mentions that he participates for the sake of his younger brothers and himself for a better life as their families have disappeared. Both reached to the submit and Lulu ran along to the location, bringing Hokaben, Bucyake and unknown to her, Kojiro's three brothers in tow for extra support. Both engaged in the fierce final duel, with everything on the line and at stake. Kojiro lost the match as his blockers were removed by Katta's combination of MaltNEXT, Super Battle Dragon Edge and Gaiheart, Galaxy Sword. His received his prize, which was a cash prize and was enough to pay for the debt. Some days after the duel, he watches Katta's duel against Lucifer. He even cheered for Katta to change Lucifer's fate and future.
Duel Masters Versus Revolution
He was offered a job in Duel Masters Land after he paid the debt and his standings at the national tournament. However, he felt a bit suspicious about the offer he was given during the time in his surveillance work and about the white castle of the park. When Katta, Lulu and Hokaben sneaks into the park to find Bucyake, he dueled Katta to stop them but lost. He let them off and provided information about the park and about the white castle.
It was later revealed that the phone call he was given was related to the Duel Masters Star Cup. He received a Duel Phone as one of the key items of the tournament and told Katta about it before the opening of the event. He then received a duel request from Duemouse and have a duel at Katta's school. At first, he almost have a deck out due to his Tenzan, Sinister Demon Dragon ability and his graveyard tactics, but won in the end by summoning Killer the Kill, Revolution Demon King from the graveyard, receiving points based by the event rules.
During the Star Cup event, Kojiro has thought of quitting as he had not achieved his goals. His brothers encouraged him not to give up and he decided to duel Katta again to regain his purpose. But in truth, he was blackmailed by the President of Duel Masters Land to defeat Katta in order to save his brothers, as Benchan had obtained the information about the true intentions of the secret organization. Even though he won and took away all of Katta's points, he gave his opponent 1 point, saving Katta from being eliminated from the competition, preventing his deck from being destroyed by Rambo and foiling the organization's plans altogether. He reunites with his brothers after they were freed.
Duel Masters Revolution Final
He has now joined the Rare Killers and is seen giving Basara a copy of Digurupion, Earth Snake to be fed by Dokindam X, The Legendary Forbidden. At first, he demanded a reason for Basara in obtaining rare cards to the point of grabbing him by the shirt. However, he let go after he felt a strange pulse from Basara (likely Dokindam X).
He appears in Episode 13 and dueled Benchan. While Benchan bounced all of his creatures with Question, Secret Revolutionary Questioner, he pulled a Death Hands, Misfortune Emperor shield trigger and used it to destroy an Aqua Surfer, then sent out Jigokushivaku, D2K to destroy Benchan's Question and used a combo with Haridelberg, Hell of D and Darth Sith K, Dark Armor and defeated him.
He then kidnaps Lulu Takigawa and has Katta go to a storage house and challenged him into a duel. Katta broke 2 of his shields, but then he sent out the Jigokushivaku, D2K, Darth Sith K, Dark Armor and Haridelberg, Hell of D as usual, and then Katta sent his Jigokushivaku into the mana zone using Natural Snare. He also reveals that he was recruited by Number 2 using a phone call and he promised to give Kojiro more power, which he agrees. However, Kojiro reveals a new trick under his sleeves; he used Sanctuary of Earth and Demon to put all of his creatures into his mana zone and evolved Jigokushivaku into Dorballom, Lord of Demons, greatly shocking the spying Lucifer and Katta, resulting in Katta's mana zone and battle zone having nothing in them. But when Kojiro is about to deal the final blow, Katta reveals a Dragon Emperor's Emblem in his hand and reveals Briking, Deluxe which destroyed his DarthRayne, Dream Knight which he used for a direct attack and set up Briking, Hamukatsuman Buster, No.1 Wind, Bosskatsu Buster, No.2 Man and Katsuemon, Blade 3 into his mana zone. Then he sends out Bosskatsu Buster, No.2 Man to revolution change into Dogiragon Buster, Blue Leader. While Katsuemon, Blade 3 is destroyed by a shield trigger Terror Pit, Hamukatsuman Buster, No.1 Wind deals the direct attack and Kojiro leaves without any answers. However, he did gave a hint to Katta about Basara might not be human any longer.
After then, Basara's possession becomes even more serious. When Leo Hyakujuu and his creature partner Damama invade the Rare Killers base, he decides to not duel him and let the idol deal with Basara.
Later on after Officer Serious left Rare Killers, he was the second one to leave as well and he challenged Basara to a duel. Basara's FORBIDDEN ~Star of Forbidden~ has transformed into FORBIDDEN STAR ~World's Last Day~ and thus he was no longer human. The transformation of the forbidden Star has shocked Rokuro and Ijiwaru Kiyomori, but Number 2, while at first shocked, later claimed that it is part of the plan. In spite of this, Kojiro managed to send out Jigokushivaku, D2K and BloodRayne, Start Dash against Basara then sends out Kill the Borof, Rebellion of K to finish him, but when Basara's turn comes, he sends out Blackout, ZERO Invasion using ZERO and finishes Kojiro with Dormageddon X, seemingly never seen again.
However the reality is he was trapped inside a subspace when Katta was encountering the same fate as him after facing Basara. He punched Katta before Katta was saved by Ryusei the Earth. He later found himself back in the Rare Killers base after Katta and Team Hamukatsu defeated Dormageddon X.
12 years after the final battle, he duels Katta's son Joe Kirifuda. His enhanced 'beast mode' scares the daylights out of Joe. However the last shield is an overpowered version of Bainaradoor which resulted in him getting defeated by Jolly the Johnny Joe's alternate win condition.
In the Manga
Unlike in the Anime, in the Manga Kojiro's brothers do not exist and he is noticeably more violent and cruel, similar to Kyoshiro Kokujo and is known for insulting opponents without remorse and punched Katta and also destroyed his deck. After his defeat under the hands of Basara and Dokindam X, The Legendary Forbidden, he was never seen again.
Duel Masters Versus
|Episode number||Opponent||Outcome||Deck name|
|Episode 4||Katta Kirifuda||Victory||Jet Black Demon Dragon|
|Episode 9||Sasori Busujima||Victory||Jet Black Demon Dragon|
|Episode 14||Katta Kirifuda||Victory||Annihilation Dragon Sword Diabolos|
|Episode 16||Lucifer||Loss||Annihilation Dragon Sword Diabolos|
|Episode 28||Hattori||Victory||Hell Destruction Dragon|
|Episode 38||Sasori Busujima||Victory||Hell Destruction Dragon|
|Episode 41||Lucifer||Victory||Supreme Slaughter - Demon King|
|Episode 44||Fuji Duema Three Musketeers||Victory||Fire and Darkness Dragons (Teamed with Katta)|
|Episode 44-45||Katta Kirifuda||Loss||Supreme Slaughter - Demon King|
His first deck was a mono Darkness deck focused on Funky Knightmares and Demon Command Dragons with additions from DMX-16's Kojiro's Power! Destro Doom Pack. He called the deck "Jet Black Demon Dragon".
His new deck for the tournament was a modified version of DMD-19 Super Victory Deck: Annihilation Dragon Sword Diabolos.
After the tournament, he began adding cards from DMR-14 Wild Dragon Gaiglen, DMR-15 Double Swords Ohginga and DMX-18's Kojiro's creature removal hell pack in the Duel Masters National Tournament. He called the deck "Hell Destruction Dragon".
For his duel against Lucifer and Katta in the semifinals and finals, he once more changed his deck, adding new cards from DMR-16極 Super Battle Guynext x Goku. He called the deck "Supreme Slaughter - Demon King".
Duel Masters Versus Revolution
|Episode number||Opponent||Outcome||Deck name|
|Episode 2||Katta Kirifuda||Loss||Destructive Darkness Civilization|
|Episode 10||Duemouse||Victory||Descent of the Destructive Demon King|
|Episode 16||Lulu Takigawa||Loss||Descent of the Destructive Demon King|
|Episode 25||Katta Kirifuda||Victory||Demon Revolution|
|Episode 31||Hakase||Victory||Demon Revolution|
|Episode 45||Narrator||Loss||Hell Revolution|
At the start of Duel Masters Versus Revolution, he used cards from DMD-22 Due-ma Start Deck: Destroyer Darkness Civilization.
He later uses a deck based on the Revolutionary race which he names "Descent of the Destructive Demon King".
He then updates it with cards from DMX-20 Deck Ultimate Perfection!! Due-Max 160 ~Revolution & Invasion~ and DMR-18 Seize the Moment, Miradante!!, which he names "Demon Revolution".
Duel Masters Versus Revolution Final
|Episode number||Opponent||Outcome||Deck name|
|Episode 13||Benchan||Victory||Most Horrifying Evil Hell|
|Episode 14||Katta Kirifuda||Loss||Most Horrifying Evil Hell|
|Episode 30||Basara||Loss||Rebellious Hungry Wolf|
|Episode 47||Joe Kirifuda|| Loss|
(Due to Joe Cheating)
|A Journey of Hunger!|
He uses a Dark Knightmare, Demon Command and Initials deck mixed with cards from DMD-33 Masters Chronicle Deck 2016: The World's End by the God of Devils. He called it "Most Horrifying Evil Hell".
His final deck was an homage to all of his previous trump cards, naming it "A Journey of Hunger!".
- His voice actor was also the voice actor of Yuuki, a rival of Boy George.
- Besides being the new Darkness duelist, his appearance is reminiscent of Kyoshiro Kokujo, an iconic duelist of the older series.
- Kojiro has a higher average win rate than Lucifer in VS.
- In episode 9 it is revealed that he is extremely shy around girls and is even scared by them.
- Episode 12 hints that while Lucifer might have French origins, Kojiro could be of Mediterranean descent.
- Besides Kyoshiro Kokujo, Kojiro might also be inspired by Kojiro Hyuga from the Captain Tsubasa series. His actor has also voiced Kojiro Hyuga.
- Coincidentally, his name is based on the historical figure.
- More so, him unwrapping the bandages on his arms in episode 16 when he faced Lucifer is similar to Hiei from Yu Yu Hakusho. Kojiro's hair turning white when he enters 'super beast mode' makes him reminiscent of the titular character from Inuyasha.
- Although in the VSR season he is shown to be playing Darkness Revolutionaries such as Killer the Kill, Revolution Demon King and Death the Lost, Demon Revolution, in episode 25 it is revealed that he still owns an impressive collection of cards he does not use:
- Draghearts such as Deathgoros, Supreme Devil Corrupt King, Deathshiraz, Devil Corrupt King and Diajigoku, Annihilation Demon Dragon
- The two versions of Jenny, the Dismantling Puppet from DMX-12 Black Box Pack
- The promotional version of Bone Dance Charger featuring Jenny in its artwork
- The promotional MODE CHANGE version of Jenny, the Suicide Doll
- The WINNER version of Hanzou, Menacing Phantom
- The promotional version of Necrodragon End of the World
- The promotional MODE CHANGE version of Terror Pit
- The promotional version of Tigermite, Bomb Devil
- Regular yet rare cards such as Devil Diabolos Double Zeta, Ultimate Awakened, Dorballom D, Demon Dragon King and Tsumitobatsu, Misfortune Hero.
- In the final episode of Duel Masters Versus Revolution Final, Joe Kirifuda drew a card based on him with an effect similar to Tsumitobatsu, Misfortune Hero, albeit stronger:
| Darkness / Creature |
■ When you put this creature into the battle zone, each of your opponent's creatures in the battle zone gets -10000 power until the end of the turn.
- ↑ Usage of Proxy Cards in the duel
Benchan ● Yohdel ● Lucifer ● Kojiro Sasaki ● Justice
Helen ● Sasori Busujima ● Dragon Ryu ● Hamukatsu
Oka Reiko ● Komei ● Gyou ● Hattori ● Lena
Dobin Sensei ● Shobu Kirifuda ● Mai Kirifuda ● Benny Haha