When Azuma Ikki returns to Japan after 10 years, he gets assaulted by a group of armed men and becomes their prisoner. Kogane Asabuki, a childhood friend, saves him with a weapon on her right hand known as Bubuki; a weapon with its own mind. Azuma Ikki, who is a Bubuki user himself, learns about the existence of Bubuki and goes on a journey alongside the companions he has found, in an attempt to find and revive Oumai, a Buranki (titan) who sleeps underground.
某天，时隔10年回到日本的少年·一希东，突然遭到武装男子们的袭击，并被囚禁起来。而救出了东的人，是青梅竹马的少女·朝吹黄金，以及有着右手形态、拥有意志的武器“舞武器”。知道了“舞武器”的存在，以及自身也是“舞武器使者”的东，与遇到的同伴们一起，为了让沉眠于地下、被称为“王舞”的舞乱伎（巨人）复活而开始行动。