Ryota Kajiki left fish cooking over a fire unattended in the hopes that it would attract Duelists to the cliffs, where his monsters were at an advantage due to the Ocean Field Power Source. While Dark Yugi and his friends were desperately searching for food, Katsuya Jonouchi caught he scent of Kajiki's fish and tried to convince his friends that the should take the food for themselves. Anzu Mazaki disagreed, but eventually everyone sat down around the food. Kajiki then emerged from the ocean and began arguing with Jonouchi over ownership of the fish. When Kajiki saw that the others were Duelists and one of them was Yugi, he realized he had made a big "catch" with his "bait" and offered to share his food with them.
Kajiki told the others about how he and his father had lost their boat in a shipwreck. He blamed the incident on pollution nearby causing the ocean to be angry. The reason he entered the tournament was to win the prize money to buy a new boat.
After the meal, Yugi and his friends got up to leave, but Kajiki threw a harpoon, which stuck into the ground just beside Yugi. He then explained that the fish had been bait to lure in Duelists and challenged Dark Yugi to a Duel.
1st turn: Kajiki
2nd turn: Dark Yugi
Dark Yugi Summoned "Imp" in Attack Mode. He then noticed that Kajiki's monster was not visible, making him unable to attack it.
3rd turn: Kajiki
Kajiki got "Devil Kraken" to emerge from the water, attack and destroy "Imp" (Dark Yugi: 2000 → 1740 Life Points) and then retreat back into the water. He described this technique as his "sea stealth attack".
4th turn: Dark Yugi
He thought that this was his best move for now and planned on using "Feral Imp" to teach Kajiki a lesson next turn.
5th turn: Kajiki
6th turn: Dark Yugi
Dark Yugi equipped "Horn of the Unicorn" to "Feral Imp" ("Feral Imp": 1300 → 2000 ATK) and switched it to Attack Mode.
Although Dark Yugi could not see Kajiki's monsters, "Feral Imp" used a lightning-based attack, so he was able to attack the Ocean and the electricity would flow through and attack all monsters within it. However "Jellyfish" absorbed the electricity and became stronger as a result, while the ATK of "Feral Imp" returned to normal ("Feral Imp": 2000 → 1300 ATK).
7th turn: Kajiki
"Devil Kraken" attacked and destroyed "Feral Imp" (Dark Yugi: 1740 → 1480 Life Points).
8th turn: Dark Yugi
9th turn: Kajiki
Kajiki Summoned "Leviathan" in Attack Mode in the Ocean ("Leviathan": 1800 → 2340 ATK).
"Leviathan" attacked and destroyed "Silver Fang" (Dark Yugi: 1480 → 340 Life Points). The tidal wave from the attack flooded Dark Yugi's side of the field. Since the moon's gravitational pull affected the tide, this covered twice as much area as usual due to the presence of the moon card. As a result, Dark Yugi was left with one Desert zone.
10th turn: Dark Yugi
Dark Yugi Summoned "Giant Soldier of Stone" in Defense Mode in the Desert ("Giant Soldier of Stone": 2000 → 2600 DEF).
11th turn: Kajiki
Kajiki suspected Dark Yugi was going to move "Giant Soldier of Stone" into another zone to create an island, giving him room to play more monsters, so he Summoned "Megalodon" in Attack Mode in the ocean ("Megalodon": 1500 → 1950) and got it, "Leviathan" and "Devil Kraken" to surround "Giant Soldier of Stone" giving it no room to move.
12th turn: Dark Yugi
Dark Yugi switched "Giant Soldier of Stone" to Attack Mode. Kajiki was surprised and reminded Dark Yugi that he could not attack any of his monsters. However Dark Yugi explained that he was not getting "Giant Soldier of Stone" to attack any of them. Instead, he got it to attack and destroy his own card, "Mystical Moon". With the moon, gone its effect on the tide disappeared, so the waters flowed out of the zones around "Giant Soldier of Stone", leaving Kajiki's monsters stranded.
Dark Yugi then Summoned "Curse of Dragon" in Attack Mode (ATK: 2000) and activated "Burning Land" to destroy Kajiki's monsters and take out his Life Points (Kaijik: 2000 → 0 Life Points) and win the Duel.
Kajiki was gracious in defeat and complimented Dark Yugi, who said that Kajiki was not too bad himself. Kajiki was then left with one Star Chip, which he promised to use to start over and work to win the prize money for his boat.
- Yu-Gi-Oh! Duelist Duel 12: "The Scourge of the Sea"
- Yu-Gi-Oh! Duelist Duel 13: "Attack from the Deep"