Danzōmaru

Danzōmaru (斷蔵丸) is one of the four guardians which guard the entrance to the Seireitei. He is the guardian of the Black Ridge Gate (Northern Gate).

Soul Society arc
Sōsuke Aizen hypnotized him and the two other guardians so he could use them to give trouble to Ichigo Kurosaki and his friends. However, he was stopped by Jidanbō Ikkanzaka.

Bount arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.

He appears again when the Bounts invade Soul Society but is quickly dispatched by the Bounts Yoshi and Mabashi.