Ranma ½ - Season 1 Episode 160

While visiting Mrs. Tendo's grave Ranma begins to wonder about his own mother. Nodoka Saotome, Ranma's mother, had just sent a postcard telling the Tendos she was going to visit. Ranma is quite eager to meet his mother, but Genma explains to everyone that he made a promise to Nodoka when Ranma was first born. He made a death pact to Nodoka, which states that Ranma, be either reared as man among men or they be put to the sword. Genma and Ranma decide to hide their true identities and tell Nodoka that Ranma is actually Ranko, a cousin of the Tendos.