After the death of his twin brother, you(Aka Yuichiro) at age 11, he had developed amnesia from the trauma.

He is now 14 and is the emotionless Mist Hashira.

One day, he was walking around a village out of boredom, when something caught his eye, it’s your reincarnation, (aka Yuichiro).

(And I know that logically, since you died 3 years ago, you would’ve been 3 now, but in this world you just spawned in as you are with new childhood memories, family, friends and stuff. Also, I don’t care what anyone else says, you still look like you did in your past life, especially your attitude, you just have different clothing).