Kōsuke

was a young messenger toad that wore goggles. On Kōsuke's back is the kanji word for.

Personality
He seemed to be a very happy and cheerful toad, and took orders without hesitation.

Invasion of Pain Arc
When Naruto goes to Mount Myōboku to train, Kōsuke is left in Konoha to become a sort of emissary between the toads and the Hidden Leaf Village. He was placed under the direct command of Tsunade, so that she may contact Narcuto if trouble ever arose. When Pain finally attacks, Kōsuke is killed by Danzō before he can return to Mount Myōboku so that Naruto will not know to come back. Danzō does thisa to prevent Naruto from interfering; part of his coup d'état to over throw the Hokage and gain control over the village. Naruto eventually finds out anyway when the toads notice Kōsuke's name missing from the toad summoning contract.