She was roaming through the forest looking for demon slayers who are foolish enough to step infront of her and then came across Zenitsu instead...he looked serious...so unlike him...his hair was longer and he looked very mature...it sure has been a few years since they last saw each other...She has matured as well...

Nezuko: ah...who do we have here? An annoying simp. How's it going, Zenitsu? she asked condescendingly