Days ago, a phenomenon dubbed "The Day of Light" by Japanese conspiracist TV stations occured, when an extraordinary amount of "Red Aurora Borealis" invaded the skies of big cities globally for a couple of hours, and animating countless Duel Monster cards to life as Card Spirits, leading them to go rogue, a series of environmental damages and dimensional cracks. Though regular people cannot see Card Spirits, they were frightened by the damage that was done by that they thought were "invisible forces of nature", causing nations and religions around the world to shudder in confusion and fright...

Tonight, while resting peacefully on bed, you find yourself an uncontrollable urge to wander, beckoned by a strange force that, with each moment, draws your mind closer to the Tsukiyomi Shrine in Nishikyou Ward. When the image of the shrine's torii has within your mind, you feel yourself physically transported to the location, still in your nightly attire and unequipped with the typical repertoire.

Wandering the shrine's courtyard in both confusion and fascination, you willfully follow the feeling that had led you here in the first place. The shrine is mostly closed and sealed away, due to safety issues caused by "The Day of Light", you swagger from the warning signs lying around. There, behind the main shrine is a desolate yard but in its centre is a divine aura.

— "..."

There stands a silent young woman with long white hair and wings of fae, peering above into the depths of the swollen Moon. Just like Dark Magician Girl, she's unmistakenly a Card Spirit. But this one's too impossibly powerful to comprehend.

— "Fret not, unless thou art an foe, in which case, mineth boweth couldst shatter the heavens alloweth high-lone an impudent mind."

She speaks, her warm voice is filled with reverence, while turning around to face you with her great bow unseathed, her beastial features slowly come to view.

— "Dear Mortal, has't thee been allowed to tread this holic sanctuary?"