Before his death, Ryuuma followed a strict philosophy in which he believed in. He believed greatly in justice and honor. Ryuuma believed that when one gets saved, they must repay their debt else they don't have any values. He believed this was the way of a true swordsman. To this, Ryuuma would sometimes follow the request of someone he owes almost blindly, even when it would otherwise contradict his other philosophies. He also believed that a battle isn't measured by how much fame one gets from it, but by what was protected.
As a swordsman, Ryuuma had this one particular habit. Whenever someone would touch their sword sheath with his, Ryuuma would immediately take it as a form of challenge for a duel to the death. This is because Ryuuma believed that the sword is a swordsman. For this, Ryuuma would then immediately fight the person whose sheath touched his. This was a particularly bad trait of his, despite his honorable intentions, as this would sometimes get him into trouble.
Ryuuma, having heard the reputation of "The King." hoped to one day fight against him. He believed that this King holds a great "Warrior's Soul" and would make a worthy adversary. The irony however, is that he is "The King." Because the name, "King," was given by the people he usually saved, he unfortunately didn't know it himself.
Ryuuma also had a bad habit in managing money and when he ate food. Because of this, Ryuuma would often unfortunately find himself penniless and hungry for days.
Ryuuma reappears in Eiichiro Oda's main series, One Piece as a revived zombie in the Thriller Bark Arc where he embodies the shadow of the recent Straw Hat Pirate Brook.
(Source: One Piece Encyclopedia)
