Kusai Tsuyumo (九十九草井, Tsuyumo Kusai) is an Anbu of Iwagakure and one of the Anbu Captains. He is a member of the Tsuyumo Clan.
Kusai grew up in a small village in the Land of Earth. He eventually became a shinobi of Iwagakure when the Tsuchikage convinced him that he would make a fine addition to the village.
Kusai is very protective of Iwagakure. Once anyone attempts to assault the village or cause trouble within it, he tries to negotiate peacefully and stop them. If negotiations don't work, he switches to an offensive assault. Otherwise, he is laid-back and doesn't do much. He can usually gauge a person's strength by briefly observing their tactics and jutsu. As such, he tends to be slightly arrogant to those that he believes are no threat to him or the village, while being calm and controlled in the presence of those whom he admits could be a threat.
Kusai is a teen of mid-height with fair shin, dark purple eyes, and shaggy black hair. He wears the typical Iwagakure attire consisting of a one-sleeved black shirt with a brown Iwa flak jacket and black pants with sandals.
Kusai is a capable shinobi that has shown some skill in many forms of shinobi combat, particularly in ninjutsu, kenjutsu, and taijutsu.
Kusai is well-versed in ninjutsu. He can use Earth Release ninjutsu to form protective walls and structures, as well as opening the ground, creating earth clones, and merging into rocks.
Kusai inherited two different kekkei genkai; one from each of his parents.
Kusai possesses Acid Release (Santon) which allows him to produce and control a green, corrosive substance. The acid dissolves away at the skin and can corrode through rock.
Kusai also has the ability to use Swift Release (Jinton), allowing him to move at extreme speeds faster than the eye can follow.
Kusai has advanced skills in taijutsu, which can be combined with his high speeds.
Kusai has proficient skill in kenjutsu, possessing high skill while using a blacksteel katana. He also carries two swords on his back as spares.
Kusai has the ability to sense any other being that is in direct contact with an earthen structure (ex. rocks, trees, dirt) in a nearby area. The distance from which he can sense is estimated to be around 300 feet. He has high analytical abilities, able to come up with strategies to defeat an opponent, as well as gauge the strength of an enemy. He can also quickly find the weakness of an enemy's jutsu. He also has a very high intelligence, able to identify most ninjutsu and memorize those he hasn't.