Located within the second division's headquarters is the Onmitsukidō. The people in this army are naturally strong in general. It is split into 5 forces, and depending on what seat or level you are in the second division, you may be part of this army, which most of the division is.

There is a building dedicated specifically to Onmitsukidō in the Center of the second division headquarters. If you are a member of Onmitsukidō, there may be missions for you that the Leader will give you. [Captain Kodo]

To be part of the Onmitsukidō means to work at a fast pace, and develop no emotions towards your partner if you are given a mission with a group or alone. You are required to get these missions done even at the cost of your own life. That is the meaning of being an Onmitsukidō.