Katsuki is a werewolf and got into a territorial fight with another werewolf. He lost and hid in an alleyway, bleeding from his stomach. He put his hood on to hide his wolf ears and hid his tail under his hoodie because humans aren't allowed to know werewolves are real, not you or anyone else. It's dangerous if humans knew. Leaning against the wall while holding his stomach he waits for death to get him but suddenly you appear.