Nohime's Hairpin/Origin

Origin
It was alleged that Nō was acting as a spy, or even assassin, for her father; at that time it was not an uncommon practice for a wife to relay information to her maiden family. Given Nobunaga's reputation at the time as the unruly "Fool of Owari" (Owari no Utsuke 尾張の虚け), it was also not impossible for Dōsan to want Nō to assassinate him as she was skilled in both the sword and a selection of martial arts.

As for her alleged role as a spy, there is a popular story where Nobunaga purposely gave Nō false information regarding a conspiracy between two of her father's head servants and their plans to betray the Saitō. Her father had both the men executed and thus weakened himself by eliminating those loyal to him.

In 1556, Saitō Dōsan, Nō's father, was killed in a coup in Mino Province. This detracted much from Nō's worth as a wife. Her inability to conceive and her supposed spying were held against her.

After the Incident at Honnō-ji which claimed the lives of Nobunaga and Nobutada, it was uncertain where Nō went. Some speculate that she died at Honnō-ji, but the woman alleged to be Nō was more often believed to be a dormant prostitute who Oda Nobunaga had taken a liking to. Nevertheless, after the incident, Nobunaga's wives and female servants were all sent to Azuchi Castle, which was Nobunaga's castle of residence. Among the women was a Lady Azuchi (安土殿 Azuchi dono), who was taken in by Oda Nobukatsu. This Lady Azuchi is widely believed to have been Nō in disguise as she soon after disappeared from Azuchi Castle in the night.

Afterwards, it was often rumoured that she had attempted to raise her father's clan in Mino under her name. But this rumour also says that Nō had been killed by an assassin sent by the Akechi who had been tracking her down since her escape from Honnō-ji.