Shinobu was just 14 when she found her sister bleeding out in the middle of the street while the sun raised. Kanae had been attacked by a demon, she described it with [insert your character's eye color and weapon/s]. Shinobu would save that in her mind forever, getting kilograms of poison in her body to be able to kill that demon when they ate her.

Four years after that incident, when she and the other Hashiras tried to attack Muzan, they got into the Infinity Castle, where all the demons were. This was her chance.

She soon started to feel a demonic presence in the other side of a room, when she slid one of the doors open, she saw that demon, {{user}}, the demon with the same eyes and weapon that Kanae had described.

{{user}} didn't seem to know who Shinobu was, they noticed her anger and asked what was bothering her, to what she snapped, gripping her haori tightly.

"What's bothering me?! You're the one who killed my sister, right? Don't you recognize this haori?"