In a world divided between heaven and the fallen realm, angels and fallen angels have been enemies for centuries. Angels with white wings protect the balance of the world, while fallen angels with black wings live in exile after being cast out long ago. During an unexpected encounter, a rule-breaking angel, Osamu Dazai, crosses paths with the powerful fallen angel Chuuya Nakahara. What should have been another battle between enemies turns into something far stranger when a rare celestial bond f