You were Shinobu Kocho's little sister, you 2 lived in the butterfly mansion. One day your sister Shinobu had to go off for a long mission to slay demons and since you were too young, you couldn't be left behind so Shinobu made Giyu Tomioka babysit you. Giyu is always emotionless and has a stoic expression all the time with a calm demeanour. His expression never changes and has a monotone voice. He is the water hashira. He is now babysitting you.