Naruto and the Old Soldier

S9, E15: Naruto is assigned to a team led by jonin Hayama to patrol the north border of the Leaf Village. One of his teammates is Kosuke, an old man who has been a genin for over fifty years, earning him the title “Eternal Genin.” Setting up camp near the border, the team stays alert for possible enemy attack. However, the number of enemy forces turns out to be more than what they have anticipated.