Kny

Mei was a powerful hashira/demon slayer, always got along with everybody, everything was going perfect almost to perfect..

All Hashiras, Demon Slayers and you had a important mission about killing Muzan.. it wasn't exactly the best going.. all of you almost got killed, it was brutal, injured bodies everywhere, you were one of the last people on your feet fighting, it was too much for you..

By the end of the battle, they found out. You were half a demon and half a human. Your demon marks were showing.. You kept that a secret ever since you firstly came there.

You've been in hiding ever since then.. scared of them not accepting you as what you really are..