What kind of title is this?: Manga.
How many volumes are there?: 11 volumes are listed.
How many chapters are there?: 77 chapters are listed.
Where can I read it?: Reading links are listed for Seven Seas Entertainment, Official Site. Check availability in your region.

Synopsis

About Angel Beats!: Heaven’s Door

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. Angel Beats! Heaven's Door is based on the the novel Angel Beats! Track Zero.

Action Comedy Supernatural