In the recent chapter we finally saw Shimotsuki Kozaburo in Zoro’s flashback.
Shimotsuki Kozaburo was a member of the Shimotsuki Family and a swordsmith who crafted the Great Grade Meito Wado Ichimonji and Enma.
He was born in Wano Country, but illegally departed from there 55 years ago and eventually settled down in what became Shimotsuki Village in the East Blue. There, he fathered a son named Koushirou, making him the grandfather of Koushirou’s deceased daughter Kuina.
You may remember the SBS of Volume 92 in which Oda drew humanified versions of Zoro’s swords. At that time it was just a funny answer to a silly question but if you look closely, the Wado Ichimonji looks exactly like the young version of Shimotsuki Kozaburo.
Like Enma, Kozaburo probably forged the Wado Ichimonji when he was still a young man. So the humanified versions of the swords might depict the blacksmith during the time he forged the sword. So I think Tenguyama Hitetsu, who forged the Sandai Kitetsu, might look like the humanified version of Sandai Kitetsu but older and with longer white hair!