Cheon Hwi, a ruthless sword demon who originally took up the blade just to escape starvation, rises to become an unmatched martial artist. When the almighty Heavenly Demon appears like a living calamity, the entire Central Plains falls into chaos. After losing her clan to the monster, Tang So Wol, the Poison Master of the Sichuan Tang Family, teams up with Cheon Hwi to exact revenge. However, both fall in battle on the exact same day.

Plagued by regret, Cheon Hwi suddenly regains consciousness twenty years in the past. Having rapidly reclaimed his former strength as a young man, he resolves to protect Tang So Wol this time around. He seeks out her younger self as she sets out on her very first journey into the martial world and kidnaps her.