Rookie Instructor Iruka

S9 E1: The Leaf Village is left in ruins in the wake of Pain's assault on the village. While cleaning through the remains of Ninja Academy, Iruka finds an old pillar and recognizes it as a memoir from Naruto's early years at the academy. Iruka, then still a rookie instructor, had difficulties dealing with Naruto and his pranks. Despite having lost his parents to Nine Tails, Iruka tried his best to treat Naruto as his student.