After a decade away, Azuma Kazuki returns home unsuspecting of the dangers awaiting him. Ambushed and captured by a group of armed individuals, his childhood friend Kogane Asabuki rescues him using a peculiar sentient weapon called 'Bubuki.' Azuma discovers he can also manipulate these weapons and joins forces with allies to awaken the slumbering titan Buranki, Oubu. This quest not only grants him newfound abilities but also unravels the mysteries surrounding the ancient Buranki, paving the way for Azuma to uncover hidden truths.