Before departing on their training journey, the only way Nodoka agreed to let Genma take Ranma from her was to promise that he would train Ranma to be "a man among men." If Genma were to fail in this regard, both he and Ranma would commit seppuku. Nodoka agreed to this and also that she would be the kaishakunin for her husband and son, hence the need to always carry the katana. She is then supposed to join them in death after their own lives are taken.
Because of this promise, Genma and Ranma are terrified of showing their true forms to Nodoka and for her to find out about their curses, although Genma is more afraid than Ranma. To prevent her from finding out, they hide in their cursed forms, with Ranma taking the alias of "Ranko" and pretending to be Akane's cousin from the countryside, and Genma assuming the identity of "Mr. Panda" and pretending to be Ranko's pet.
Nodoka saw Ranma from behind as a male while he was with Akane, but threatened him as she thought that he was trying to molest her. However when he used the Tatami Flip technique on his mother to escape, she realized that it was her son and excused his behavior as signifying his manliness. It was arranged for the two to meet face to face with Genma kept from interfering, but Happosai slipped a sailor outfit onto Ranma, which Nodoka then saw him in from behind. She slipped a man's death robe onto him to prepare for his seppuku, but he escaped. (She was confused as to why Ranma fled, to which a sarcastic "isn't it obvious" was given) The family then decided that to prove his manhood Ranma would deliberately peep on Akane while she was bathing, which Akane agreed to, while Nodoka would watch. She at first thought that Ranma was after Akane's clothes when he slipped and crashed into the laundry hamper, but then saw that he was actually disappointed that Akane was not naked as he had expected, but wearing a bikini. Reassured that Ranma was a man, mother and son would have been reunited then had not Happosai again interfered with his Happo Ring of Fire after being held back from peeping on Akane. Nodoka doused the bombs with a showerhead, causing Genma to slam Ranma through a wall with a sign. Although she then saw Ranko, the name "Ranma" from Mr. Panda's sign was on Ranko's forehead, leading Nodoka to start to suspect that they were the same person.
Ironically, it was Genma who brought about the reunion between his wife and son through his attempts and machinations to steal the Saotome family treasure.
However, she decides she won't force them to commit seppuku so long as Ranma stays interested in girls and continues to fight like a "man amongst men." After this, Genma and Ranma live for some time in her house, until it is destroyed (in an unshown scene) by Shampoo, Ukyo Kuonji and Kodachi Kuno, who are trying to take what they believe is an engagement ring. She and her family then move back in with the Tendos.
Nodoka is a gentle, attractive woman, who very closely resembles Ranma's female form, noticeable after Nabiki comments on how similar they look during Nodoka's first visit to the Tendos. Nodoka has shoulder-length hair (medium brown in the anime) that she wears up and typically dresses in a kimono. She always carries around a long bundle, the family katana covered by a wrapping.
Nodoka wants nothing more than to see her son, to whom she has not spoken since he was two years old. She is not the only one who has been affected by the ordeal, however. Ranma has tried on numerous occasions to talk to her as a man, but Genma repeatedly foiled his efforts. For Nodoka, her glimpses of Ranma as a male have been fleeting at best, usually because he was pursuing some other objective at the time, or attempting to escape her.
When she met Akane, she quickly approved of her and offered to help with her cooking skills so that she could make a better wife for her son. She also dotes on "Ranko" and has aided her to similar ends. In her most notable incident of the sort, she took Ranko shopping to find her more suitable feminine clothing, including a bra, something Ranma would never normally wear. But the existence of Ranko's identity created a strange situation for Ranma when Ryu Kumon arrived. Posing as Ranma, the rival martial artist had sought out Nodoka for his own ends. She was initially convinced as to the imposter's identity as her son, but became suspicious after seeing him interact with Akane Tendo and was eventually told the truth.
Nodoka, while kind and slightly old fashioned, has a very strange set of principles. She seems to despise perverts, but is willing to allow and even encourage Ranma to perform perverted acts such as peeping on girls, play with women's underwear and even have him spy on Akane while she takes a bath. It is explained, however, that she sees this as the way her son can "prove" his manliness. Her actual view of a true epitome of masculinity seems to lie much closer to the savage, imposing, independent and semi-militaristic Ryu Kumon.
In contrast to her enthusiasm to see Ranma, she has displayed an often comical lack of concern for her husband, going as far as to not notice him right next to her, and making almost no response at all when Ryu Kumon said he was dead.
She is not particularly skilled with katana, though. She routinely fumbles it when unsheathing it, usually sending it flying or at the very least dropping it, and her strokes are quite uncoordinated. She has strength in her blows, being able to stab through the inner walls of an ordinary house or cut a rolled up tatami in half with one stroke, but with very little finesse. She has, upon drawing it, accidentally thrown it into the air, nearly impaling Ranma, who was off-screen.
===Genma Saotome Nodoka was very reluctant to let her husband take her young son away from her, but after accepting his promise to train Ranma to be a man upon pain of death, fully embraced her role as ensuring that both of them lived up to their end of the bargain. Despite their long absence, she is shown to have been faithful to Genma. However after he stopped updating her following their acquiring the curses at Jusenkyo, she began to get worried, more so for Ranma than for Genma.
To be added
Nodoka briefly appears in the OVA ending song, A Pure & Honest Christmas. In the ending credits she arrives at the Tendo Dojo and after removing the snow from her umbrella is escorted in by Soun and the sight of Nodoka terrifies Genma (who is fortunately in his panda form).
Although not mentioned by name, "Ranma's mother" is mentioned in the live-action special. When Akane asks Genma about Ranma, Genma explains that Ranma's mother died years ago and Ranma promised her he'd become a man amongst men. However, this turns out to simply be a lie from Genma hoping to deepen Akane and Ranma's relationship with it, and Ranma's mother is still alive, but neither of the Saotomes have seen her for a long time.
- Nodoka means "calm" or "peaceful", two words that fit her personality perfectly. Saotome means "rice-planting girl", which applies more to Ranma's condition.