A boy named Yugi Mutou solves the Millennium Puzzle which turns in into the "King of Games".
A criminal escapes from jail and takes Anzu as a prisoner. Yugi shows his other self by using the Millennium Puzzle as he challenges the criminal to a Shadow Game in order to get Anzu back.
Seto Kaiba is a new student in Yugi's class and he is also a Duel Monsters (a card game) expert. After he steals the Blue-Eyes White Dragon from Yugi's grandfather, Yugi challenges him to a duel where the cards are real. The game remains a tie and Yugi gets his grandpa's card back.
Honda buys a watch for Miho and he gets lucky because he gets the last one. When a guy that collects watches sees that there aren't anymore, he steals the watch from Miho only to be stopped by Dark Yugi right in time. Yugi challenges him to a Shadow Game for the watch as the watch collector loses and Yugi returns the watch to Miho.
A man from ancient Egyptian comes at the museum where he sees Yugi with the Millennium Puzzle. He travels in Yugi's mind to see if the puzzle really belongs to Yugi. In there, Dark Yugi challenges him to a game where the man from Egypt must find the real door which has the Millennium Puzzle in it. In the end, the man from Egypt loses and he tells Dark Yugi that he really is the owner of the Millennium Puzzle.
Shadi, the man from Egypt, challenges Yugi to a Shadow Game, with Anzu's life as the prize.
The popularity of Digital Pets leads to a contest, and Honda trains Miho's pet, so they can take the paid trip. Meanwhile, Yugi is worried for his friend Haiyama, who seems to be pressured into some shady business by the bullying Kujirada. But all is not what it seems...
Yugi is kidnapped by Kaiba, and forced to duel the first of his four Game Masters, Count Ridley Sheldon. Can Dark Yugi defeat his doll monsters?
The gang is concerned and confused when they see Jonouchi with a gang wielding yo-yos as weapons. Has he turned his back on his friends?
Anzu clashes with the beautiful but sadistically strict Ms. Chrono, and organizes a petition to change the school rules. But Chrono's underhanded counterattack ruins the petition--until Dark Yugi steps in.
Yugi's friend Warashibe is obsessed with Capsule Monsters, and Miho. When she spurns his advances, Warashibe decides to eliminate her friends--his competition for her affection.
Game show champion Ryuichi Fuha (Kaiba's second Game Master) moves to the gang's high school. Although he seems friendly, Ryuichi's tactics for arousing Dark Yugi soon turn dangerous...
Fraudulent psychic Kokurano has his eyes on Anzu. Though Anzu doesen't believe his predictions at first, her desire to see her mysterious savior (Dark Yugi) leads her right into Kokurano's grasp.
When she realizes that Yugi is her mysterious crush, Anzu invites him on a date to an amusement park, intending to put herself in danger to see Dark Yugi. But she finds herself in real danger when a mad bomber challenges Dark Yugi to a twisted game of balloons and explosions.
A new girl named Risa Kageyama wants to become Yugi's girlfriend (much to Anzu's anger). But Risa is actually intent on obtaining Yugi's rare Violet Hectate card.
Jonouchi has a crush on Miyuki, the nurse taking care of his sister Shizuka. But when a corrupt doctor fires her, Jonouchi can't expose him, or Shizuka will be kicked out of the hospital.
Kaiba's third Game Master, famous model Aileen Rao, challenges Dark Yugi to a game of Rijinhai. Irene prides herself on taking away the most important things from the ones she defeats--if Yugi loses, he loses Anzu...
Yugi befriends bullied youth Imori, and the two discover the forbidden game Dragon Block. The evil game overcomes Imori and he challenges Dark Yugi to a game with his soul itself on the line.
With Honda's support, Miho enters a popularity contest against arrogant school beauty Kaoruko Himekoji. Soon Kaoruko resorts to cheating, but when she hurts Miho, she incurs the wrath of Dark Yugi. (Bakura makes a cameo in this episode)
Kaiba's butler Daimon, an old man kept alive through machinery, duels Dark Yugi as the final Game Master. In the process, he reveals how Kaiba used to be, and implores Yugi to restore his kindness.
Kaiba kidnaps Yugi's grandpa and dares him to come to Death-T, an amusement park full of death trap games. But Yugi is hesitant to put his friends in danger.
The gang heads through Death-T, making their way through a laser tag game with actual lasers, and a game of wits with a giant killer robot.
With Honda seemingly dead, an enraged Dark Yugi battles Mokuba, Kaiba's little brother, in Capsule Monster Chess.
With his grandpa and friends at stake, Yugi duels Kaiba, and his three Blue-Eyes White Dragons, while Jonouchi and Miho battle Ryuchi and Aileen. With his friends' support, Yugi pulls off the unbeatable combo--Exodia.
Yugi and his friends meet Ryo Bakura, a gentle new student with an interest in role-playing games. Little do they know the danger that dwells within him...
Yami Yugi aids the others, reduced to figurines, against Dark Bakura and his RPG's boss, Dark Master Zorc.
Even when seemingly defeated, Zorc rises again and threatens to overwhelm the gang. It is up to Bakura to defeat his evil counterpart.