Ten years ago, on a training trip in the country, Genma stole Ukyo's father's okonomiyaki yatai (food cart), leaving her behind and breaking the arrangement he and her father made. However, before this Ranma and Ukyo were friends, though Ranma never knew she was a girl. Shamed and ridiculed by her peers, Ukyo decided she wouldn't like boys, dressed and lived as one, and devoted herself to okonomiyaki-style martial arts. After a heated battle, Ranma discovers her true sex. Meanwhile, she discovers that he does not get along with his "uncute" fiancée, Akane. They reconcile, and she falls in love with him again. Ranma still treats her as only an old friend, and her plots to win him over are usually less violent than those of his other suitors. Although she lives to cook okonomiyaki and runs a restaurant, "Ucchan's," to that end, Ukyo would give it all up to marry Ranma.

(Source: Wikipedia)