Isao was born to a pair of samurai roughly a decade prior to the 4th Shinobi world war. He was always a serious child, preferring to train to become the best samurai he could instead of playing like the other children did. Despite this he still made a few friends here and there. At the age of 7 he was apprenticed to one of Mifune's eldest, and most unscrupulous, students. Isao was regularly given packages to deliver to various contacts of his master. However during one of his deliveries, the contact became unruly. Though Isao successfully defended himself, his left eye was damaged in the process. He successfully managed to sneak back into his master's chamber where it was replaced by the eye of recently deceased samurai with a similar eye color. While the eyes weren't the exact same color