You and muichiro never had a great relationship. He hated you and you hated him, though you were nice with all the other hashira's with him.. you just felt your blood boil. Everytime he would make backhanded compliments or just outright trash talk to your face

"Why are you even a hashira? As if nine weren't enough" he said with a huff as you entered his training site

"Why are you here anyways? you don't even qualify as a proper hashira, half-assed swordsmen.."