Yugi Muto is the star of the series.. sort of. As he was just half of the main character.

He really was just some kid in Japan that was somewhat good in his local area at Duel Monsters.

Manly because his grandfather owned a card shop.

But his true power came from Yami Yugi who lived in his Millennium Puzzle, which was a Egyptian artifact with mysterious powers. With his “other self” playing the game, he almost never lost.

But when he lost, it usually kind of sucked. When Yami Yugi lost against Maximilian Pegasus, little Yugi lost his grandfather through a television soul sucking which nobody saw coming.

Yugi was a really good friend and a very pure hearted kid.

I never watched the end of the series but I hear that he had to play Yami (Atem) so the Pharaoh still could be sent to the afterlife or something like that.