Angels are among us. They are scattered across the globe, living in our neighborhoods, observing humanity—the Earthian—in crisis...Chihaya and Kagetsuya have known each other since their days at school. They are friends...and possibly more. These two angels roam the world, compiling lists of the positive and negative traits of humanity. In the process they become involved in the lives of various humans, full of despair: An astronaut about to venture on a dangerous mission, a sorceress running from the mafia, and a mysterious artificially created human are just a few of those beings who Chihaya puts himself at risk to help, much to Kagetsuya's dismay. But after a meeting of angels, it is discovered that a dreaded disease is plaguing a growing legion of angels. Salvation possibly lies in the fallen angel Lord Seraphim—and as Chihaya and Kagetsuya search to find him, he turns up in the most unlikely of places...