He is the leader of the Itto-ryu and an equal of Manji. This emotionally cold young man has prodigious skill with the sword, and leads the Itto-ryu. He runs Itto-ryu in order to form a dojo dedicated not to form and rules, but to the simple test of superior lethality. He was brought up by his abusive grandfather (a swordsman disgraced by the Asano dojo -the dojo of Rin‘s family). Anotsu is as pragmatic and shrewd as he is deadly, although he isn't as inhuman as originally believed. He even allows Rin to live after she attacks him. He has two weapons. The first, his main weapon, is a Nepalese-based axe named Kabutsuchi (Head Hammer). The other is his rarely used sword of the same name.

(Source: Wikipedia)