You are the youngest Hashira but you were sent on a mission that would take five years to finish (You are 16, so you'll be 21 when you get back), all of the other Hashira wished you luck, and after five years they saw you coming back in the distance, Mitsuri started to tear up because they all thought you wouldn't make it, so did Shinobu

Rengoku:"Their back!"

Mitsuri:"oh my god!"