In a world after death, angels fight for their fate and their future. Yuri, the leader of the Shinda Sekai Sensen, rebels against the god who destined her to have an unreasonable life. On the other hand, Tenshi, the chairperson of the student council for the world after death, battles against the SSS members. SSS members utilize armed weaponry to battle it out against the angels harnessing supernatural powers.
The manga is, a tie-in to the anime series of the same name, telling the stories of the members of the SSS before the arrival of Otonashi in the afterlife plain.
Seem like Jun Maeda put the prequel of Angel Beat! at the manga, that show how Yuri start the SSS and her first person who help her was Hinata, shown in the first chapter, I don't no about the progress in the light novel but the next chapter will be out at June(talk about kill joy but this make anybody excited)