After dying to save a stray dog, Japanese schoolboy Ren Takahashi is reborn in a medieval fantasy world with an extraordinary gift: his spirit can slip free of his body while he sleeps. What begins as harmless night roaming soon grows into a secret power to possess animals, shapeshift into their forms, and even wear the skins of other humans. But when a dark force threatens his village, Ren must master his abilities and fight from the shadows… without losing himself in the skins he now wears.