Kosuke Maruboshi

is a genin of Konohagakure, whom others called the.

Background
Kosuke had been a genin for over fifty years, thus the reason others called him the Ten-Thousand-Year Genin. During his time he had served under the Second, Third, and Fourth Hokage. At other points, he fought alongside Jiraiya and Sakumo Hatake.

Abilities
Even though he is a genin, he was skilled enough to become a jōnin. When he was younger the Second Hokage taught him many of his techniques, such as Water Release: Water Dragon Bullet Technique, and Water Release: Water Encampment Wall. He also learned the Shuriken Shadow Clone Technique from the Third Hokage. In his older years, he had a fake left leg, which when taken of would reveal a hidden blade. He was skilled with a sword.

Konoha History Arc
He was placed on a team alongside Hayama Shirakumo, Tekuno Kanden and Naruto Uzumaki to guard the borders of the village after Orochimaru and Sunagakure's invasion of the village.