Our story begins with a girl named Yumo and her classmate, Yusha, who accidentally wander into a dark dimension called Youshanding.
In their confusion, Yumo and Yusha were beset upon by menacing lifeforms known as Chaos Beasts. On the brink of demise, the two were rescued by Leo, a stone lion warrior whose mission is to protect the Human Realm from the looming threat of Chaos Beasts.
As Leo helped Yumo up, she absorbed his Dragon Vein energy, altering her appearance and granting her strange, unwanted powers. She accepted an offer from Boss, Leo's superior, in the hopes of returning to normal.
Yumo then spent her summer vacation working part-time for Boss and defending the world from Chaos Beasts.
While fighting off these dimensional invaders, Yumo and Leo encountered two other Kunlunians - Bahet and Le Viada. The two Kunlunians wreaked havoc in both the Human Realm and Youshanding, brainwashed by a mysterious force.
The culprit behind the brainwashing? A young girl named Nemea - a powerful AI capable of manipulating Dragon Vein energy.
After the toughest battle of her life, Yumo managed to defeat Nemea and save the Human Realm.
Little did she know, her story was far from over...