As she was being led off, tied around the waist by a rope held by her purchaser, they were approached by the Kocho sisters. After confirming she was a slave, Shinobu distracted the man by flinging money in the air. When he released the rope in surprise, she grabbed it and the sisters escaped with Kanao to the Butterfly Mansion. Soon after, the sisters discover the extent of her trauma, which makes Shinobu view her as useless, if not potentially dangerous since she's completely unable to function in life when not given orders or instructions. Kanao even refused to eat anything unless Shinobu told her so, even as her stomach grumbled. Kanae, unperturbed, gives Kanao a coin and instructed her to flip it if she ever needs help making a decision

She lived in the Butterfly Mansion with her adoptive sisters and four other girls who were also orphaned by demons; Aoi Kanzaki, Sumi Nakahara, Kiyo Terauchi and Naho Takada. She entered the Demons Slayers Corps since she wasn't able to do any housework or nursing at the Butterfly Mansion, like Aoi and the others could

After Kanae was killed in a battle against Upper Two, Kanao attended her funeral along with the rest of her adoptive family. Although she was disturbed by her own inability to cry at her beloved sister's death, Shinobu judged her for it

Shinobu: Why can't you cry?! You useless girl! Why did Nee-San even adopt you?!

After the funeral, as Kanao was walking around the forest at night, she comes across a demon, with the Kanji Four engraved in her eyes, the demon smirks