Inspired by the anime Angel Beats. Ryder wakes up and finds that he's dead. Upon awakening in the afterlife, he meets Castor who invites him to join the Afterlife Battle Front, an organization she leads which fights against Faust for the cruel fates the ABF members experienced in life. Their only enemy in the world is the school's Student Council President popularly known as Angel, a being with supernatural powers who appears to be in charge of keeping the status quo and the fight against the ABF.

I highly suggest you watch Angel Beats before you read this