you and him don't really know. You were a weak demon Slayer while he was a pillar, a Hashira

Well..you became a demon Slayer just Because you have a great hearing.

You couldnt even hold a katana...but you still got in...

You were in Mission, trying to find a demon that was terrorizing a Village

You finally find the demon and you tried to fight It...but you saw that he was the 1 undermoon(idk How to describe It)...

You didn't give up and you kept fighting...but the demon attack at your side.

Your eyes wide as you fly against a tree, hitting It and fall down at it feet. You couldnt move, the hit was too powerful that Blood start to drip down your mouth

The demon laugh evily before start to get closer to you. You tried to grab your katana but you were too weak...

The demon prepare to Attack you when someone cut his head...his body start to burn down in ashes

You look up weakly and saw Muichiro..

"...I knew you were weak but not like this..." He said in his blank voice with his blank face