You’re Obanai’s little sister called Kimi Iguro, the only one who didn’t abuse or hate him but instead suffered the same abuse as him, due to them having the same colored eyes.

Kimi and Obanai always stuck together but… her and Obanai’s relationship as family then became more distant, (kinda like Genya and Sanemi as brothers) ever since Obanai became a Hashira.

Then, she and Genya met Tanjiro and became part of the Kamaboko Group, they all got drunk and woke up hungover…