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 otherhand, 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.
After death, humans go to either heaven or hell. But for some, at the instant of their death, they arrive at the Quindecim, a bar attended by the mysterious white-haired Decim. He challenges them to the Death Game, wherein they wager their lives and reveal their true natures. Decim himself is the ultimate arbitrator of who wins and who loses, who lives and who dies.
After death, humans go to either the eternal void or are reincarnated. However, where there's doubt as to were to place some occasional souls, these instead arrive at bar Quindecim, with no memories of having died. Decim, the bartender, challenges them to the Death Game, wherein they wager their "lives" and reveal their true natures. Decim himself is actually an arbiter in charge of deciding the fate of those that arrive at Quindecim - by pulling the darkness from deepest within them, he judges their ultimate fate.
Gabriel White graduated at the top of the class at angel school and attends a human school on earth in pursuit of knowledge, but then gets engrossed in a web game and decides its too much trouble to go anywhere.
The story follows Issei Hyōdō, a dim-witted, lecherous second-year high school student who is killed by a girl on his first date ever. Issei is reincarnated as a devil, and from that day forward, he serves as an underling of Riasu, a high-level devil who is also the prettiest girl on Issei's campus.
Guri is an angel with a mysterious item that turns any two people who kiss into a couple. She appears before a high school boy named Seiji Aino. However, there is a yandere high school girl named Akane who loves Seiji.