In the novel, she is a kunoichi (female ninja) sent by Tokugawa Ieyasu to spy on his political enemy Ishida Mitsunari before the Battle of Sekigahara.
[citation needed] In the 2017 film Sekigahara, based on Shiba's novel, Hatsume became a female ninja in Iga after serving as a maid of Toyotomi Hideyoshi's mother.
She then fell in love with the character of Ishida Mitsunari and began working for him in the Western army.
The director of the movie Masato Harada wanted to create a "boy meets a girl" type of romantic encounter.
[1][failed verification] According to Shiba's novel, after Ishida Mitsunari's death at the Battle of Sekigahara, she disappeared from the historical records and her existence is debated.