Hakase Ochanomizu
御茶ノ水おちゃのみず 博士ひろし
Civilization(s) WaterWater
Affiliation Duel Masters Land
Voice Actor 杉山 紀彰
Noriaki Sugiyama
Signature Card(s) Baron Spade, Invader
Vegas Dollar, Super Eureka
Master G, Super Eureka
Dokindam BLACK (Illusion only)

Hakase was first introduced in the Versus Revolution season of the Duel Masters Anime.

He is part of the secret society of Duel Masters Land.


He was a tech genius in charge of the technical, programming and designs of the entertainment spots of the park.

Hakase's gambling personality

Hakase thrills through gambling

He have a love of gambling, enjoying a thrill of low probabilities, with a high risk high return strategy. However, he cannot tolerate losses, shown when he lost against Lulu Takigawa through the robot he controls and programmed. He is also shown to have a malicious side, doing anything to achieve his goals and felt that Katta will become a great threat to their plans if the Revolutionary cards were found. After his Gachirobo defeat and his personal defeat, he bears a deep grudge against Katta. Due to losing his family at a young age, he shows disdain towards reality and prefers to have robots on his side. However, he treasures his late grandmother's advice and the card he received from her, to the point that he was furious that Zon-san transforms it to its S-Rank Invader variant of the said card.

Despite having great confidence, he has a cowardly side, shown when he realized if he did not end the strike, he might face the President's wrath. In a duel, he has a habit of saying 'Bingo' if he manages to get the desired cost of his opponent's card, which reflects his gambling personality.

Despite the personality flaws, he still values his friendship with Basara, even going as far to stop him from creating the World of Zero.



Young Hakase

Young Hakase witnessing his grandmother's death

As a young child, Hakase lost his parents, leaving him under the care of his grandmother. He received one of the cards, Vegas Dollar, Super Eureka from her and treasures it. However, his grandmother eventually passed away, causing him to be left alone.

He participates in many organised tournaments, becoming one of the Duel Masters champions. However, he was not satisfied by the victories he gained and turned to gambling duels, which mostly contributed to his gambling personality. After he was part of the secret society of Duel Masters Land, he programmed many robots, with one of them, the gigantic gatcha robo "Gachirobo" as his strongest one in the underground city of the park.

Duel Masters Versus Revolution

He first appears under the shadows when he opens the gates for Basara.

He makes his formal appearance with Basara and Rambo, creating and controlling a robot to stop Lulu from searching Katta Kirifuda. He even programmed it to destroy Lulu's card shop, attacking Benchan and Hokaben. Through the robot, he duels Lulu but lost. Lulu destroys the robot, causing the transmission to be cut. He got frustrated that their plans were foiled, with Rambo commenting it as unbelievable.

He made contact to Ultra Buddara, the owner of the hot springs not to let Katta and the group find one of the Revolutionary cards hidden there. When his plan failed again, he let off Buddara for once and programmed another maniacal experiment he created for this after surveying Katta's practice duel with Gyou. After Buddara got the armor and attacked Katta and the group instead of settling in a duel, Hakase got a bit embarrassed when he realized that he made a mistake in the programming of the armor. He also send Gachirobo to deal with them but failed again.

As a final measure to hide their real plans and get hold of Katta and Dogiragon, Flaming Revolution that Katta managed to awaken the dragon's spirit, the group organized the Star Cup event. He then cries over his failed attempt to get hold of Katta and his Revolutionary cards, swearing revenge on him. He also participates in the Star Cup event.

Dogiragon "7-Hit combo"

Defeated by Dogiragon "7-Hit combo"

In the new attraction in the park which also functions as a casino, he was disguised as a dealer, prompting Katta to duel him based by the Star Cup rules. He reveals himself to Katta and his team when Lulu found his offer suspicious. Katta found out he was the one who sent Gachirobo to attack him and decided to duel him. During the duel, Hakase was able to predict Katta's probabilities, allowing him to have an upper hand. He continues to provoke Katta about his low chances of winning. However, after Katta awakened Dogiragon, Flaming Revolution once more, in which the dragon breaks his final seal chains and revealing its second Revolution skill, he got defeated by Katta's "7-hit combo". He was carried away by his robots after being knocked out, with Rambo noting his loss atop the white castle.

He later awaits orders from his leader about the land matters and the card shop Lulu Takigawa owns. In the new attraction with the robots he controls, he got annoyed by Katta tempting onto one of the attraction structures. During one of the conversations, he noted that someone had hacked into their systems to undercover their dark secrets, he was told by the boss not to duel Lucifer due to his overall dueling strength.

At one time, there was a strike occurring in the underground city. Realizing that Rambo's earlier actions (in episode 20) was the cause of the strike, he kicks him and panics as he knew their next actions, in which the President left the grounds to charge himself from other electrical resources. During the Halloween event in the park, he communicated to Duemouse not to remove his cover at the celebration, with Rambo acting as a fail safe measure. In the movie studios, he dueled against Kojiro Sasaki in a movie studio as he doesn't agree to the movie director's script. He uses Master G, Super Eureka ability to increase the odds of preventing it from leaving the battle zone, but got defeated by Kojiro's Death the Lost, Demon Revolution Revolution 0 ability, compounded with a direct attack.

Due to his incompetence in getting rid of Katta, he got kicked out by Duema Land President along with Rambo. The trio then awaits revenge against him in the new fortress. He analyzed the new S-Rank Invader executives that were currently residing in the fortress, even sending a map with the coordinates to Dokindam X to Basara's Duel Phone. He decides to handle the S-Rank executives along with Rambo. However, both are blocked by Zon-san's zombies, which also lets Katta and his friends to leave the stage quietly without a duel. He got enraged that Zon-san transforms his grandmother's card to its S-Rank Invader variant. He was defeated by Deadzone, S-Rank Zombie, in which he recognized it as Basara's signature card before being transformed.

He was seen on one of the small attractions related to the park in the epilogue, meaning that he escaped the underground city after the battle in the fortress.

Duel Masters Versus Revolution Final

He picked the Dokindam Gacha along with Rambo in Katta's dream and it turns them into a Due-Man with Hakase and Rambo in the same head. They gave Katta a difficult situation with Dokindam BLACK and Vegas Dollar, Roaring Eureka X but the last shield was a Dogiragon Chance that destroyed their creatures and they were defeated by Katta's Dogiragon Silver of Fate.

His true appearance in the anime is in order to stop Basara from turning the world into ZERO along with Rambo. Before their defeat Hakase lauched a series of missiles trying to destroy Dormageddon X, Forbidden Armageddon but the card was indestructible so they were seemingly killed. However, both sent a message about Basara's location to Lucifer before the duel. After Katta defeated Dormageddon X, he and Rambo found themselves back in the construction site and hugged each other in joy of being alive.

12 years after the Dormageddon X incident, he was part of Basara's motor grand prix race crew. He almost got into an argument with Ijiwaru Kiyomori until Joe Kirifuda cuts in between them. He somehow recognize Joe's surname until Joe reveals himself to be Katta's son, much to his and the others surprise and shock.


In the Manga series, Duel Masters Land doesn't exist and thus he is the mechanic of the Rare Killers. He defeated Benchan with his Invasion rush deck featuring Vegas Dollar, Super Eureka but despite that he confronted Katta with Master G, Super Eureka and pushed him to the brink with Ragnarok, the Clock, he was defeated when Katta Kirifuda reversed with Dogiragon, Flaming Revolution and Diehard Ryusei of Invincibility.



Episode number Opponent Outcome Deck name
Episode 11 Katta Kirifuda Loss Hakase's Strange Gamble
Episode 31 Kojiro Sasaki Loss Hakase's Fantastic Gamble G
Episode 42 Zon-san Loss Hakase's Fantastic Gamble G

Through the first robot he sent to fight against Lulu, he uses a Water Civilization deck based on the Invader race, demonstrating the Invasion mechanic for the first time.

In his official duel against Katta, he uses his own Invader deck based on Magic Commands and Liquid People Sen. His deck is mostly themed to be like a gambling table, with creatures that activates abilities based by the cost of his opponent's card.

In his duel against Kojiro, he added cards from DMR-18 Seize the Moment, Miradante!! and DMX-20 Deck Ultimate Perfection!! Due-Max 160 ~Revolution & Invasion~.

Duel Masters Versus Revolution Final


Episode number Opponent Outcome Deck name
Episode 32 Katta Kirifuda Loss Forbidden Star Dokindam Gacha
Episode 40 Basara Loss The Final Battlefield!

He uses a Darkness Fire deck with a Dokindam Gacha Figure in Katta's Dream.

In his real appearance in VSRF, his deck contents were not known except for Vegas Dollar, Super Eureka, since he was quickly defeated.


  • As a tech genius, he was like Benny Haha in Shobu Kirifuda's era and Gennai Saiba in the Victory V season of the anime.
  • Shacho bears a striking resemblance to him, although their relations were unknown.
  • He shares the same voice actor as Sasuke Uchiha in Naruto Shippuden.
  • His loss rate in the anime is 100%, the same as Duemouse and Bucyake, the lowest of any major character in the VS Saga, excluding duelists that only dueled once or twice.
    • This is in no means that he is a bad duelist since he is of considerable status in the anime.
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