The story in short
Yasuo was the student and bodyguard of the elder Souma, the last master of the wind technique. One day he left his post to chase a battle with Noxus that never came. When he got back, Souma was dead, killed with the wind technique itself, and everyone pointed at him.
Yasuo cut his way out and spent years as a fugitive. One of the people who came after him was his own brother, Yone, and Yasuo killed him in a duel. With his last words Yone set him on the trail of the truth, and it wasn't what anyone expected: Souma's death was an accident, and Riven caused it. Yasuo's name was cleared, but the guilt over his brother never left.
