Makina was working as a blacksmith for the famous guild "Silver Wings" when she was expelled by a guild member who did not take good care of her weapons (it was cheaper to get them at a weapon shop than to hire them). Makina is at a loss, but his childhood friend Aria, an adventurer, invites him to join her guild, "Rainbow Butterfly". There, his blacksmithing abilities are put to use, and together with the guild members who have Makina's weapons in their hands, they rise to become the strongest.