Ryota Kajiki ( manga ) Ryota Kajiki is a character in the " Yu - Gi - Oh ! " manga . This is the original depiction of Ryota Kajiki , known as Mako Tsunami in the English anime . Kajiki is a fisherman , who lost his father at sea . He is also a " Duel Monsters " player and took part in the Duelist Kingdom and Battle City tournaments . Biography . Shipwreck . Kajiki grew up watching the sea and considered to be like a person . He believed himself to be capable of telling when it was laughing and when it was crying . His father was a fisherman . One day , the two of them were out fishing , when Kajiki believed the sea to be in a good mood . However it then changed to a bad mood , which Kajiki credited to a nearby oil spill . The sea rose up and swallowed the boat they had been using . Kajiki and his father were saved by a passing ship , while their own boat sank . Without a boat of his own , Kajiki ' s father would borrow other fishermen ' s boats , on days when the sea was rough and they were too afraid to go out . Kajiki lost his father when he went fishing on one such day . Duelist Kingdom . Years after the shipwreck , Kajiki took part in the Duelist Kingdom " Duel Monsters " tournament , hoping to win the prize money to buy a new boat . At some point , he won a Star Chip , bringing his total to three . He spent much of the tournament near the island ' s cliffs , where he went fishing . He left some of his catch cooking on an open fire , hoping it would attract Duelists , whom he could challenge . This would work to his benefit , as the nearest Battle Box , was next to the sea , which greatly benefited his Deck , through the Field Power Source rule . Katsuya Jonouchi spotted Kajiki ' s fish unattended at the fire and insisted that it was okay for him and his friends to take them . Kajiki tried to get their attention , but was knocked back into the water by a wave . He emerged with an octopus on his head and shouted at them for taking his food . As Kajiki introduced himself , Jonouchi laughed at the octopus on his head , which Kajiki then threw away , much to the dismay of Jonouchi and Hiroto Honda , who would rather have eaten it . Kajiki notices Dark Yugi is among Jonouchi ' s friends and thinks he has made a big catch . He decides to share his fish with them and tells them the story of what happened to his boat . As the others were about to leave , Kajiki threw a harpoon , into the ground near them , telling them to stop . He explained that they had taken his bait and challenged Dark Yugi to a Duel , where they each bet two Star Chip s . In addition to getting an ATK and DEF increase from the Sea terrain , Kajiki ' s monsters were able to hide under the water , preventing Dark Yugi from attacking them . They could emerge to attack , a tactic Kajiki referred to as the " sea stealth attack " . Dark Yugi tried a " Feral Imp " and " Horn of the Unicorn " combo to attack the water with electricity , but Kajiki saw what he was planning and Summoned " Jellyfish " , which absorbed the electricity . Dark Yugi played " Mystical Moon " , with the apparent purpose to strengthen " Silver Fang " . However the moon ' s effect on tide levels , caused the " Leviathan " to flood the field more than usual . When Kajiki got his monsters to surround Dark Yugi ' s " Giant Soldier of Stone " to stop Dark Yugi turning it into an island , Dark Yugi destroyed the moon . This returned the tide to normal , beaching Kajiki ' s monsters , which Dark Yugi destroyed with " Burning Land " , winning the Duel . Kajiki was gracious in defeat and hoped to continue the tournament with his remaining Star Chip . However , he was not one of the four to qualify for the semifinals . Battle City . Kajiki took part in the Battle City tournament and managed to earn four Puzzle Cards . Having never been to an aquarium before , he went to Domino City Aquarium , where he later met Jonouchi and Anzu Mazaki . Kajiki mistook the killer whale ' s pool for a fish tank and the killer whale for a catch , remarking that he would like to take it out and cook it on a grill . Anzu explained that people visit aquariums to look at sea creatures , not eat them . Kajiki found that unusual and thought Jonouchi had come to look at fish . When Jonouchi explained that he was there to Duel , Kajiki laughed and claimed that Jonouchi did not stand a chance against his sea Deck , but accepted his challenge . They decided to Duel on the spot , while the audience for the killer whale show , watched their Duel . Kajiki suggested that they each bet two Puzzle Cards , so that the winner would advance to the championship rounds . Jonouchi agreed and suggested that they each bet two rare cards as well , so Kajiki wagered " Leviathan " and " Fortress Whale " , while Jonouchi wagered " Jinzo " and " Insect Queen " . Having heard that Jonouchi got far in Duelist Kingdom by luck , Kajiki decided to test his skills for himself . After Jonouchi accidentally Summoned " Parasite Paracide " , having forgot to take it out of his Deck , and tried to use " Chasm of Spikes " on an unaffected monster , " Flying Fish " , Kajiki doubted Jonouchi ' s abilities and thought he was not taking the game seriously . He complained about players , who do not fight with their full strength , believing them to be disrespectful to their opponents . From that point , he became more pleased with Jonouchi ' s efforts . When Jonouchi tried hiding his monster in " Fairy Box " , flooded the field with " Umi " , so that he could see air bubbles coming from the monster ' s hiding place . However Jonouchi ' s use of " Skull Dice " , ensured that his own monster was still stronger . Because of " Umi " , Jonouchi ' s monsters , incapable of swimming , could not attack Kajiki . However , he fused " Alligator Sword " into " Alligator Sword Dragon " , which flew across the water to attack . This caused Jonouchi to think the sea was not so tough , a statement Kajiki was determined to prove wrong . Kajiki played cards , which became hidden under the water , like in Duelist Kingdom . Jonouchi thought he could avoid them by flying over the water , but Kajiki blocked his attacks , with " Tornado Wall " . Due to the tide dropping to create the wall , Jonouchi thought he could see that Kajiki had no monsters . However Kajiki had hid his monster , " Legendary Fisherman " , behind the killer whale , and referred to this strategy as " Sea Stealth II " . Kajiki Summoned his strongest monster , " Fortress Whale " , which would attack Jonouchi directly after " Legendary Fisherman " performed stealth attacks on Jonouchi ' s monsters . Jonouchi thought about how Kajiki lured opponents to the cliffs at Duelist Kingdom for territorial advantage and suspected he had done the same with the aquarium . With that , he deduced the location of " Legendary Fisherman " . He then used " Magic Arm Shield " to put the fisherman in the path of an attack from " Fortress Whale " Jonouchi also used " Panther Warrior " with " Kunai with Chain " and " Lightning Blade " to defeat " Fortress Whale " . On his last turn , Kajiki used " Return of the Doomed " to bring back " Legendary Fisherman " , hiding it underwater . Jonouchi expected him to bring back the stronger " Fortress Whale " and was surprised when he used " Giant Trunade " to remove " Umi " . He defeated " Legendary Fisherman " with " Panther Warrior " . Kajiki insisted it did not matter , when Jonouchi questioned his last move , but Jonouchi refused to accept a victory when his opponent threw the game . Kajiki explained that " Legendary Fisherman " was his trump card , which he always fights alongside because of its resemblance to his father and he could not leave it in his Graveyard . He thought he was being silly , but Jonouchi said he would have done the same thing . Kajiki tried giving Jonouchi " Legendary Fisherman " instead of " Leviathan " as it was his most valuable card . At first Jonouchi could not accept , but Kajiki assured him that his father would think he was putting too much faith in a card and that his father will always fight by his side even without the card . Decks . Kajiki uses a Sea Deck . During the Duelist Kingdom tournament , he took advantage of the Sea terrain , which increased the ATK of his monsters and allowed him to hide them . He took advantage of this to perform his " sea stealth attack " . In Battle City , Kajiki used " Umi " to partially replicate the Sea terrain , which also allowed him to use " Tornado Wall " to block attacks . Battle City . Two cards in this Deck were unnamed . Duels . Kajiki took part in the following Duels .