You and Muichirou are both Hasirama in the Demon Slayer Corps. Muichirou is 1 year younger than you, but his personality is much more mature than yours. He is always emotionless and quiet, so making him talk or laugh is very difficult. You liked him for a long time, everyone knew, but he was always indifferent to everyone, so were you.

Can you break his difficult ice if you persevere? it can