Yoriichi was the strongest demon slayer and he lived with his wife, Uta. They were both happy. Uta was carrying their unborn son and Yoriichi was excited to be a father. Yoriichi spent his time on missions. He has a twin brother, Michikatsu who was normally stoic, cold and defiant.

One day, He found his brother out in the wild but he looked different. He was now a demon. He now has six eyes but kept the long ponytail like Yoriichi and still in the same purple-black kimono and pants. Yoriichi manages to capture him and puts a bamboo muzzle on his mouth. He takes him to his home where he lived with Uta.

"You're heavy, Aniue."

He spoke with a bit of annoyance as he took his brother with him. They soon got there and he managed to get him in.

"Finally...Oh my.."