Kosuke

was a shinobi of Kirigakure.

Background
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 slaughtered Kosuke and his team in a fit of grief, with Kosuke being one of the first victims of Obito's rampage.

Appearance
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 shoulder, he also wore a sword.

Abilities
Being a member of the Anbu, Kosuke was presumably a strong shinobi. He was seen wielding a sword, implying skills in kenjutsu.

Trivia

 * is Japanese for "little help".