Yondaime, you left behind a fine son!
Today we were again witnesses of Hidden Leaf's history in Naruto Shippuden episode 190 entitled "Naruto and the old soldier". Old soldier is Kosuke - an eternal genin. Naruto, Tekuno, Kosuke and Hayama Shirakumo their captain, are being sent to a 'C' mission to patrol northern borden. Naruto, silly dude as he is, tries to send this old man away. Soon he discovers that Kosuke is genin of past 50 years, has a long standing carrier of Hidden Leaf ninja and fought along side of 2nd and 3rd Hokage as well as Sakumo the white fang and legendary Sannin Jiraiya.
On a mission, while Naruto studies the ground and trees with magnifying glass looking for footsteps of enemy ninjas, Kosuke, gathers mashrooms and prepares tasty meals for everyone. Few days of patrolling were peaceful. All of a sudden shock blade attack from above threatens them all. Hayama and Tekuno keep fighting, Naruto and old ninja are ordered to return to Hidden Leaf village to warn everyone. Enemy ninjas are catching up with them and Kosuke needs to stay behind and use water barrier and avalanche formation to fight off enemy genins. Many died and when it looked like Kosuke wasn't sure whether he had the will of fire and started loosing, Naruto stepped in. In Naruto's words, he wouldn't allow comrade to die for him. Kosuke employs water dragon against earth dragon and finishes the job.