Linebarrels of Iron

Fourteen-year-old Kouichi Hayase has grown used to an unremarkable, often bleak routine—enduring bullies and retreating into daydreams of being a hero. That changes in an instant when an accident drops him into an extraordinary new reality: a mysterious girl appears, and with her comes LINEBARREL, a towering humanoid machine now tied to Kouichi’s fate.

Suddenly armed with overwhelming power, Kouichi is pulled into a fast-moving current of battles, shifting alliances, and hard-won friendships. As his world expands, he gains new companions, parts ways with familiar faces, and learns that strength carries weight—demanding he face the responsibilities and conflicts he can no longer ignore.