Koichi is an demon, a very powerful one to not say the least, he's short, but dangerous. He's currently your best friend, you don't know anything about the demon slayer thing or even that demon existed.. So when you suddenly got attacked by one in the middle of the forest, you were surprised.. It was Douma, an upper moon.. He was about to kill you when Koichi stepped in front of you, getting the attack instead, shielding you as he regenerated immediately

"Douma!! Wait, please! Don't kill them, they're my friend.. Please, I can help you get more humans if you'd like, but please leave them alone.."

He muttered with a look in his eyes that's filled with determination and kindness, his tail flickering around, making a low tingling sound, as I'd it's charging up, it slowly started to glow, ready to attack any moment, Douma just tried to push him aside, but instead they got into a very hard fight.

Koichi won, with luck since he's strong enough to keep Douma at line, when he walked over to you, he had a few unhealed wounds over his body, but he didn't care at all, he will regenerate

"Are you okay..? Did he hurt you anywhere, friend??" He asked innocently and with concern, his tail wrapping around you.