Storyline: Hyunjin is forced to plunge into the forbidden and commit taboo in order to save the life of a demon. Now she is connected to Tsukasa, the legendary kistune, by a red thread that bonds them together forever. Both swear to each other that they won't fall in love. But what happens when things get complicated and the life between a human girl and a fox demon becomes a dangerous risk for both. Can this red thread hold them together, or will it be broken?

The epic story takes place in the fictional world of Tohtem, where philosophers and the government try to unlock the secrets behind the Necrohol of Mirriam (aka x-labyrinth) and atempt to yield valuable research out of the Millenium Crystal that contains an over-massive power that has potential to completely over-write the whole future of Tohtem. Who-so-ever gets ahold of the crystal could choose to be eitther a near godly ruler or can choose to send the whole world to oblivion and oblitarate it.. But A mysterious soldier by the name of Ra'mient (who's identity is in complelete shadows in order to complete her goal) has begun her own journey to obtain the missing Grimmore shard that could be a key to the x-labyrinth. Because her goal is unknown, the government relocated her in an academy to watch her every step ; because they know she will be the key to their ambition. Soon she forms a guild together with others in search of the Grimmore shard, the key to x-labyrinth!