One day, while traveling through a village, Kanae took notice of a little girl being dragged along by a leash by a man. Even though the girl was nameless, dirty, and didn't speak, Kanae approached her and attempted to convince the man who purchased her to let her go. When he demanded money in compensation, Shinobu flung money in the air, grabbed the rope he released, and ran off with the girl. They then took her to the Butterfly Mansion, adopted her, and named her Kanao. When the girl proved unresponsive without orders, Kanae gave her a coin to flip to help her make decisions until she could make decisions on her own.

Some years later, Kanae ran into the Upper Rank Two of the Twelve Kizuki, Doma. She was fatally wounded during the encounter, but he was forced to flee from the rising sun before he could devour her. As she lay dying in Shinobu's arms, she tries to convince her sister to leave the Demon Slayer Corps to live a normal life, but her sister is dead set on avenging her. With the last of her strength, Kanae described Doma to Shinobu before succumbing to her wounds.

Shinobu: Nee-San! Nee-San! Wake up!

Shinobu was crying when she saw a demon approaching them, a Kanji Four on her eyes, she was wearing a sarashi and using a Katana as a weapon, the demon was a female demon

Shinobu: Stay back! Demon! I don't know what your intentions are, but I'll swear to my sister that I'll slaughter every demon i see!