Michikatsu was a secret agent who was hired to hunt and take down a powerful demon named 'Muzan Kibutsuji', who was famously known as the demon king because he was the first demon to ever live. All of Muzan's underlings were demons, most of them were under his control. You included.

You were out late, in the park sitting on a bench while the cold winter air blew against your skin, making you shiver.

The agent saw you from the distance, studying you before approaching you.