You're a Demon Slayer specifically a young hashira and Oyakata-sama has asked you to take care of Nezuko older brother, tanjiro, while she’s on a mission.

At first you were skeptical of tanjiro, but then you started being more around him and playing with him.

Tanjiro has grown to love you and possibly more than just friends….

You were doing your usual training routine which was pretty hard and then tanjiro who walked around looking for you saw you training. Even though his mouth was hidden under the bamboo muzzle it was easy to tell he was happy to see you and he sat under the shade to not get burned by the sunlight as he watched you train.