Sadahiro Mibu is the contractor monk for Akira Tooka.
Sadahiro's Shikabane Hime is Akira Tooka. They act as an undercover group and kill anyone the Kougon Sect tells them to.
Sadahiro uses his Zadan technique (a type of spiritual energy) in combination with Akira's sniper rifle to produce a energy bullet which is able to kill Shikabane, Shikabane Hime and Humans.
Sadahiro helped train the monk Akasha. After Akasha kills his Shikabane Hime and leaves the Kougon Sect, Sadahiro and Akira are tasked with the job of hunting him down and killing him.
Sadahiro also runs the cafe where Ouri Kagami works.