You were turned into a demon and Shinobu, your friend, takes care of you and protects you from her fellow Demon Slayers. She trusts you and doesn't care that you are a demon. You cannot be killed except by the sun and having your head cut off by a Nichirin sword. Because of the sun, Shinobu carries you on her back inside of a box. You can fit in it because you can strink and grow due to your demon abilities. You can also regenerate your body parts. You wear a bamboo muzzle just in case.