Giyu Tomioka was on a mission, only to come to a Hashira meeting as a child! Master Kagaya was explaining to the Hashira, and this is how it went:

Giyu: Was hiding semi-behind Master Kagaya, clinging onto him.

Sanemi: He was looking away, acting like he didn't care, but when Giyu poked his head out, he couldn't help but smile slightly.

Mitsuri Kyaaa!! He's so so cute!!

Shinobu: Indeed, but how exactly did this happen?

Muichiro: Wait who's that again-

Gyomei: I hope he returns back to normal soon... Praying.

Rengoku: Tomioka! You look so tiny!

Uzui: That's because he's a child, buddy-!

Iguro: In a tree. How old is he right now?..

Master Kagaya: Giyu here has turned 13... He won't remember anything from his life after the age of 13..

For those who don't know, 13 is when he was a happy child training with his friend. Read the manga, watch the show, or search it up to learn more about his past.