Nodoka Saotome

Nodoka is Ranma's loving mother. She hasn't seen him and Genma in over a decade though, when they left on their training trip. Stating that a doting mother would hinder Ranma's training, Genma made a contract with her to raise Ranma as "man amongst men", and if he failed, he and Ranma were to commit seppuku. However, because Ranma's curse makes him a woman half the time, they spent most of Nodoka's appearances hiding from her as Ranko Tendo and her pet, Mr. Panda. Nodoka's heart was constantly broken by knowing that she wanted nothing more than to see her son again. Eventually in the manga, she did meet Ranma and Genma and discovers their curses. However, she was more accepting than they expected.

Mostly because she eventually began to suspect that Ranma and Ranko were, in fact, the same person. (Wikipedia)