Kanna, in the form of a small, pale girl, is the first, and longest lasting, of all of Naraku's incarnations, and the most trusted. Kanna is recognized easily by her emotionless expression and white clothing. Kanna is formed from mu, giving her neither yōkai properties, emotions, or a presence. Kanna seems fully aware of existing only as a servant to Naraku, though due to her lack of emotions, does not seem to care. Because of this, Kanna is the only incarnation Naraku truly trusts, telling her important information about his actions and allowing her to give orders to his other incarnations and pawns. His trust in her is also shown when it is hinted at that she is allowed to keep her own heart, as he had to tell her to destroy herself rather than doing it himself with her heart. Despite her loyalty, in Chapter 415 of the manga, Kanna appeared to have abandoned Naraku. Though Akago confirms this was done of her own free will, Kanna still remains loyal to Naraku.
Kanna carries with her a demonic mirror, with which she can steal the souls of those reflected in it. Once a soul is trapped within her mirror, Kanna can control their host bodies to her bidding. The people whose soul were stolen are almost unrecognizable from normal people. Should a powerful soul, such as Kagome's or Kikyo's, be locked into the mirror and overflow it, the mirror will start to crack, forcing Kanna to release all souls currently trapped within. It is later shown that the mirror can create powerful rays of light to blast at Kanna's enemies. The mirror has other purposes as well, such as reflecting any attack it catches(however it seems that one of the few attacks that Kanna's mirror can't reflect is Kagome's Hama No Ya as shown in episode 42 of the anime) or observing to goings on of the world. The most powerful of the mirror's powers, however, is the ability to create a glass demon that can copy the abilities of whatever it happens to reflect. Kanna, however, receives all damage in the glass demon's stead.
Interestingly enough, Naraku seems to always create his plans while keeping in mind not to have Kanna harmed, despite however an important role she plays. Naraku only uses Kanna twice for battle, the first being just after her introduction to test Kagome's soul, and the second being for her to destroy InuYasha's Tetsusaiga. During the latter attempt, in Chapter 480 of the manga, Kanna is ordered by Naraku to commit suicide, shattering herself and the glass demon she was currently using into thousands of tiny shards. One of the shards hits Kagome's right eye, and using it Kanna directs her final thought into telling Kagome how to destroy Naraku, the only time shown Kanna has betrayed Naraku. While Naraku comments Kanna had no care for either living or dying, Kagome states Kanna did not wish to die, and perhaps developed feelings of her own over time.