When Ryu's father was killed practicing one half of a paired school of martial arts that Genma invented, Ryu spent the rest of his life training himself to master the Yamasenken in hopes of tracking Genma down, taking the Umisenken and then building a new dojo to the memory of his father. When Nodoka mistook him for her long-lost son, he tried to take advantage of that to get what he wanted. But losing to Ranma revealed to him the ugly truth behind the 'Senken Schools' and so he left Nerima, a sadder but wiser man.