A massive earthquake ravaged Japan's mainland and destroyed most of Tokyo, sinking three-quarters of it into the ocean. Ten years later, the story starts with Igarashi Ganta, a seemingly ordinary, unassuming middle school student attending Nagano Prefecture's middle school. An escapee, a survivor of the great earthquake, Ganta has no memories of the tragedy and has lived a simple, normal life. This all changes one day when a strange man covered in blood and crimson armour…