The ultimate atheist who does not allow himself to be controlled by his past, he makes his own destiny. He had many visions because the Millenium Items such as the Rod (He was the wielder of the Millenium Rod in a past life, three thousand years ago.) and the Tauk (to show him fighting Yugi, Pharoah Atem in his past life) showed visions to him, still, he believes they are mind tricks played on him. His parents died when he was ten and he was sent to an orphanage. Determined to turn thier life around, Seto challenge Gonazaburo Kaiba, the reigning chess champion and buisness tycoon, to a game of chess. Seto made a deal with Gonazaburo. If Seto won the match, Gonazaburo would adopt him. Seto won and being adopted did not conclude Seto's hardships. Seto was overworked while Gonazaburo trained him to inherit is company, KaibaCorp. During this long process, Seto became cold and heartless.
The ambitious man aquired the last name Kaiba and he took over his step-father's company by using the company's board of directors "The Big Five." He turned KaibaCorp into a gaming company instead of a company that makes instruments for war. Also Seto plays and loves Duel Monsters a card game and he will not settle for second best. Seto is always obessed with beating Yugi but he never surmonted him. He has an affinity for using the rare Blue Eyes White Dragon monster card and he has all three copies in the world in his deck.
When Seto Kaiba was in the orphanage, he told his brother Mokuba, to toughen up and not to expect anyone to help them out in their time of adversity. Instead of praying or begging, Seto used his superior intelligence to climb out of skid row and become one of the most prosperous buissness men in the world.