A war between humans and demons once left both sides seriously injured. Now, the smoke of war has dissipated, but many problems have been left to be solved one by one. In order to win the war, humans have forged a large number of powerful weapons, which people call "God-taught Magical Equipment". After the war, the whereabouts of these powerful weapons became the primary problem that needed to be solved. Everyone agreed to hand them over to the seal protector for safekeeping. Dan Heng (voiced by Hirakawa Daisuke) and Dan Fei (voiced by Nakahara Mai) are brothers and sisters. As seal protectors, they took on the responsibility of keeping the strongest weapon "Tian Xing Sword", but they also brought disaster to the two. In the end, Tian Xing Sword fell into the hands of Mie Tian Hai (voiced by Guan Zhiyi). In order to recover the magic sword, Dan Fei embarked on a journey, during which she met Lin Xue Ya (voiced by Toriumi Hirosuke) and Shang Bu Huan (voiced by Suwabe Junichi).