But while Ryumyo was very talented, he was also the polar opposite of Lung in personality. Ryumyo was a firebrand favoring immediate action, while Lung was a restrained contemplative favoring patience. Ryumyo also gave himself up for servitude to the elder dragon in exchange for more knowledge and secrets, but soon came to a point when Lung could teach Ryumyo no more, save for the deepest secrets which Lung judged to be inappropriate to teach to such an emotional and impulsive pupil.
The opposing natures and the debt of servitude eventually strained the relationship to the point where they parted ways. Lung released Ryumyo from his service, and told Ryumyo that he must learn on his own, while Ryumyo accurately believed that Lung was holding back and left feeling betrayed - Ryumyo reportedly left in a fit of temper, and left a large mess that Lung was forced to clean up.
The rift between them grew larger as millennia passed. Ryumyo saw Lung as an old backstabber jealous of his youth and energy, while Lung saw Ryumyo as an emotional upstart with no self-control. These opposed personalities explain the differences in the way each of their controlled organizations achieve power. The Yakuza under Ryumyo's leadership go for big, short-term results, with violent and direct action. The Triads under Lung's leadership often take a longer-term strategy, sacrificing immediate gain for future growth.
Reportedly, the manalines around the Pacific Ring of Fire were subtly manipulated around China by Lung, preventing the natural disasters that devastated Japan as a result of Ryumyo's actions, which were born either of ignorance of the manalines or arrogance from exploiting them. On the other hand, the Yakuza and Imperial Japan achieved economic and political power quickly under Ryumyo's influence, a feat that has yet to be matched by Lung's lumbering efforts.
It is said in the Far East that the more a person dislikes someone, the more polite that person will be in his presence. The two dragons are the pinnacles of courtesy and polite etiquette in each other's company. Take that for what you will.