Yusei Fudo is mostly calm and cool at all time and he will fight for his friends and beliefs that is why his friends respect and admire him for this and his honor and great dueling skills.
Yusei Fudo greatest rival is Jack Atlas, who was a childhood friend and later his best friend. However late rin life, Jack stole Yusei Fudo best monster card, "Stardust Dragon", and ran with Yusei D-wheel to New Domino city. He was a founding Member of the Enforcers (Team Satisfaction in the japanese orignal ), a former gang that defeated the underworld of Satellite.
Ever since the enforcers Yusei has been using the same cards. Some of his Friends such as Crow Hogan, Jack Atlas, and Kalin Kessler ( Kyosuke Kiryu in the japanse original) say that Yusei is becoming kind of predictable. Even though many people think Yusei has weak cards, Yusei knows that each card can be strong when used correctly.
Yusei is a meber of the Signers, a group of five people chosen by the Crimson Dragon each 5000 years for a titanic battle against the Dark Signers, servants of the evil Earthbound Gods.