Kuro Fukase, who has suffered countless betrayals from the harsh world, is emotionally broken. His only source of familial love came from the two Ayakura sisters, Toiro and Iroha, who lived in the same building. Unfortunately, they became victims of a devastating arson attack, and now only exist as delusions in Kuro's mind as he continues to harbor resentment for the world.
Everything changes on one cold Christmas Eve, however, when Kuro meets a peculiar and cheerful girl named Sera Himeura, an enchanting witch named Yume Furusuna, and a strange black creature. He soon learns that he is one of twenty "Instant Bullets," special individuals granted the power to destroy the world.
But the living weapons do not share the same vision. While some want to protect the world, others, including Kuro, are determined to obliterate it. In a suspenseful tale of past trauma, crumbling morals, and warped romance, what fate does the world hold when the powerful Instant Bullets turn against each other?
