From DMP:

When happy-go-lucky Shiro is suddenly murdered, he finds himself summoned to heaven by the small God Kami-Sama. The two hatch a plot to form a "family" with the addition of a beautiful ninja named Kuro. Kuro has his own troubled past. Will these three lonely misfits find a way to overcome their differences and forge a lasting bond?

This volume contains a second story called G.E. about students training to be taimashi, and the quest they embark on.