Yasumi

Yasumi was created soon after Dan Kato's death as his first major foray into cloning and genetic experiments and was widely kept a secret from society. Many of Orochimaru's other attempts at experimentation failed such as his attempts at giving children the Mokuton (minus Yamato of course), so Yasumi grew up fairly lonely. When Yasumi was 10, Orochimaru brought in a baby girl to the fold, Renge. Little did Yasumi know that Renge was Orochimaru's biological child. Soon after, a mysterious doll-like boy who claims to have come from the moon named Harin also makes his way into the fold. When Yasumi is 13, the horrors of Orochimaru's experimentations are discovered and Orochimaru with the kids in tow, defects from Konohagakure.

Yasumi continues to grow up, struggling with his own sense of identity as Orochimaru's clone and being isolated from the world at large aside from the Akatsuki, Renge, Harin, and of course Orochimaru himself, are soon roped into Orochimaru's upcoming scheme to start his own Hidden Village. However, at 18, Yasumi decides he's had enough and runs away from Orochimaru when he gets a chance to do so. Trying to set off on his own, he runs into Anko Mitarashi who mistakes him for Orochimaru at first glance until she realizes he's much too young to be him, but still apprehends him and takes him to Konoha.

After being brought into Konoha and questioned thoroughly, Hiruzen is brought up to speed on Yasumi and begins treating him like a second chance at redemption with Orochimaru, projecting all his guilt and regrets onto him. He takes Yasumi in, keeping him fairly under wraps from most of the village as to not freak others out and puts Yasumi to work as an assistant for him.