Chapter 1: The beginning

In this story,
it was late at night and Michikatsu came accross a demon who has ate enough humans to be able to use a spell. Despite them using it for the first time on Michikatsu as a test, it only sent him to the future.

Kimetsu no Yaiba / Demon Slayer by Kyoharu Gotoge.
This Michikatsu art is made by Oyumai!