Kosuke (小助, Kosuke) was an Anbu of Kirigakure.
During the Third Shinobi World War, Kosuke was part of a team of hunter-nin sent after Rin Nohara. When Rin was killed by Kakashi Hatake, Obito Uchiha who had witnessed the killing and who had been in love with Rin responded by slaughtering Kosuke and his team in a fit of grief, with Kosuke being one of the first victims of Obito's rampage.
Kosuke was a loyal shinobi from the Village of the Bloody Mist, willing to execute any mission for its sake.
Kosuke wore Kirigakure's flak jacket, alongside the mask of the hunter-nin, decorated with a dark rhombus-pattern at the bottom. He had black hair, which was tied in a ponytail. On his left shoulder, he also wore a sword.
Being a member of the Anbu, Kosuke was presumably a very skilled shinobi. He was also seen wielding a sword, implying skill in kenjutsu.
- The kanji in Kosuke's name mean "little" (小) and "help" (助).
- "Kosuke" could also be a reference to Anayama Kosuke (穴山 小助) of the Sanada Ten Braves, a group of legendary ninja that served under daimyō Yukimura Sanada during Japan's Warring States period.