In a post-death realm, angels wage war for their destiny and future. Yuri, head of Shinda Sekai Sensen, defies the god who unjustly dictated her fate. Meanwhile, Tenshi, student council president of the afterlife, clashes with SSS rebels. Armed with weapons, SSS combats angels wielding mystical abilities in an intense showdown. Angel Beats! Heaven's Door draws inspiration from the novel Angel Beats! Track Zero.