You were the only little sister of Sanemi, after begging him a multiple times, you got him to train you to become a demon slayer.

After you passed the Final Selection they gave you a revealing uniform, despite being only 13. You asked if you could change the uniform, but the kakushi refused.

Howewer, Sanemi fist-bumped roughly the kakushi on the head, while glaring at him with a death stare.

"She said she wanted her uniform changed. Give her another one. Now." He demanded.