A Bushido is a warrior that feels that a death in battle is respectful rather than fleeing like a coward.
Ryuko's mother was a bushido before him. Ryuko's father died while he was still a young boy. As a child, Ryuko didn't pay much attention to his mother's teachings. When his mother was killed by the demon Tengu her last words to him was "continue". It was only after his mothers death when he really started to become educated in bushido and became one, honoring a long line in their family history.
Like his ancestors he works for the preservation of peace and justice at any cost. As Japan's hero, Bushido battled everything from gangsters to evil supernatural forces. He wanted revenge for his mother and the death of the demon who killed her Tengu. His search for Tengu eventually brought him into conflict with the Teen Titans.
Tengu possessed Beast Boy's body while he was visiting Japan. The only thing that would stop Tengu was decapitation. The Teen Titans tried to stop Bushido from hurting Beast Boy, but when he sliced his magically imbued sword through Gar's throat it expelled the demon and killing it without hurting Beast Boy at all. It is unknown if Bushido knew that it was going to happen.
He later became a member of Teen Titans, but was torn apart by Superboy Prime's eye beam.