Kusushi

is a bespectacled medical-nin from Konohagakure.

Appearence
He wears the standard high collared, full body uniform of the Konoha medical ninja.

Abilities
As a medical-nin, Kusushi presumably has a high level of intellect, is well-versed in medical ninjutsu, and has excellent chakra control to perform medical procedures.

Sasuke Retrieval Arc
He, along with a team of medical ninja are sent as medical support to the Sasuke Retrieval Team. He meets Kakashi Hatake while he is returning to the village with Naruto and informs them of the condition of the other team members.

Mizuki Strikes Back Arc
Mogusa along with Mitate, Iyashi, Mogusa and a few other medical-nin were deployed from the hospital to save Asuma Sarutobi, Kurenai Yūhi and the others after their encounter with Mizuki. They were able to give them first aid on the stop and then later relocated them to the hospital to recover.