Jirō

is a Konohagakure genin and a student failed by Kakashi Hatake.

Background
Put in a team with his brothers led by Kakashi, Jirō failed in his new teacher's test and then he was restrained for the punishment. His brother Tarō is assured by him to eat the lunches their teacher left out. Having exactly followed his orders, Kakashi fails Tarō and his brothers. Sometime later, Jirō and his brothers thank Kakashi for sending them back to the Academy, as they realise what he was trying to teach them, much to his surprise.