Angel Beats!

Yuzuru Otonashi wakes in what appears to be a high-school campus with no memory of his life or death. Yuri Nakamura, who leads a rebel group called the Shinda Sekai Sensen, recruits him to fight the student-council president known as Angel, whose supernatural abilities enforce the school's rules, and by extension the God who condemned them all to this afterlife. The other SSS members carry their own unresolved pain from lives cut short, and anyone who finds peace simply vanishes.