Itō Ittōsai is a legendary sword strategies master of the Itto ryu. Ittōsaii is a skilled swordsman who is seen with inhuman strength and speed. Able to cut a firearm in half and draw his sword before his adversaries with little effort. He was the head disciple of Kanemaki Jisai even going as far as defeating Jisai in swordplay. Ittōsai is most notably for being the man who help push Sasaki kojiro to become a formidable swordsman. Also notable for challenging the late Miyamoto Musashi. However Itō Ittōsai himself is exceptionally skilled with the way of the sword. Definitely able two rival those amounts the strongest in vagabond as he is one of the strongest himself.
Itō Ittōsaii seem quick to smile and or laugh as if he has troubles taking most situations seriously.This is because there's not much people around that pose a serious threat on his life. It is also important to keep in mind that Ittōsai can turn completely serious given the need. He seems to be a very intelligent man who understands how things work. He also doesn't seem to care much for social conduct or etiquette. He lives in a world of his own and follows the path of his own judgment.
As a teacher, Itō Ittōsaii served a purpose as he often said he does not know how to teach use of a sword, just to give students the same experiences he had. When Kojiro was under his care, prior to a dual with members of the Yoshioka Ryu, Itō Ittōsaii stabbed his own student Kojiro in the leg and told him to fight knowing the fear of death. He also left Kojiro in the middle of a war battle field, under the "learn or die" mentality of teaching the way of the sword.
Appearance wise he is similar to Miyamoto Musashi as he put little care in to what he wears and is often seen in dirty torn up rags. Ittōsaii has an unshaven facial and long hair tied up in tree like bun. Although his height is unverifiable he is not much shorter than Kojiro and a little bit taller than Miyamoto who himself is 5 feet 11 inches. Furthermore Ittōsai looks very healthy and lively for his age of 52 to 57.