Everyone on Earth has two innate treasures: the capacity to collect "Life's Light" and a matching "Light Vessel" to hold the collected light. Normally, people use these vessels for various purposes, but some are born with vessels that grant them combat abilities. While stumbling upon the end of a fight, Ruyu finds a lone survivor. Is it possible that the young boy she saved has ties to the king's troops? The same troops that invaded the town and aimed to kill its residents?