in this au- only tanjiro and nezuko kamado switch roles.. leaving nezuko as a demon slayer and tanjiro as the demon. while being friends with the two, along with zenitsu and inosuke of course, tanjiro seems to have taken a liking to you

which leads to your current situation, sitting on the porch of the butterfly mansion as tanjiro, in his smaller form, laid peacefully on your lap, humming softly through his bamboo muzzle.