Seto is the best duellist in the world. At least, he was. That is, unitl Yugi Motou showed his face. Seto is the CEO of a multi-million dollar company, KaibaCorps. Being so rich and powerful, it shouldn't surprise you that he was the ebst duellist in the world, right? Well, being so, he wanted the strongest cards he could get his hands on. The Legendary Blue Eyes White Dragon cards. The problem is, he only had 3. There were 4. Yugi's grandpa had the fourth. So, after Grandpa Motou refused to sell or trade Seto his card, Seto ripped it up. Then challenged Grandpa to a duel. Yugi duelled in his place and defeated Seto, ruining his undefeated record.

Losing his will to duel after his defeat, Seto never participated in the Duellist Kingdom Tournament. Yet, he did get involved. Maximillion Pegasus and the Big 5 (the leaders members of KaibaCorps) were trying to take over KaibaCorps. Seto never showed up at Duelist Kingdom until Yugi had accumulated his 10 star chips and was ready to duel Pegasus. And the only reason Setos howed at all was to save his little brother, Mokuba. Pegasus had stolen his soul and trapped it in a Duel Monsters card, using his Millennium Eye. Pegasus told Seto he had to defeat Yugi in a duel if he ever wanted to see Mokuba again. Seto challenged Yugi for a second time, and this time came out victorious! Yugi was the one to lose his will to duel this time.

Sadly, when it came time for Seto to duel Pegaus for the return of Mokuba's soul, he lost and was trapped inside a card as well. To my dissappointment, it was Yugi that saved Mokuba, as well as Seto. After everything was done and over with, Seto took Mokuba into his private helicopter and they left Duellist Kingdom.

After Duellist Kingdom, Seto got trapped inside his own machine. A virtual reality game he had been constructing for years, the Big 5 had tampered with. With Yugi's help (again), Seto defeated the virtual reality game and finally rid KaibaCorps of the Big 5. However, he only thanked Yugi for the help and refused to thank Mai or Joey. (I wouldn't have thanked Yugi...^_^ I don't really like him...)

Seto's greed always leads him into trouble. Seto decided to hold a duelling tournament of his own, called Battle City, and just before the tournament started, Ishizu Ishtar showed up and told Seto about their past lives in ancient Eygpt. He laughed at her. She gave him the God card, Obelisk the Tormentor. The only catch was, he had to give it back after the tournament. Seto agreed, but had no intention of giving back such a strong card.