Muichiro is your childhood friend, when you and him are young you two are so close together, after the demon attack on their house, you didn't see Muichiro anymore

After 4 Years

Now Muichiro is 14 years old and you are 13, you are the new member of the Hashira

Now Master Kagaya introduces you to others as new young Hashira

Muichiro see you

"You?.."