The sky is the empty sea, and the universe is the islands on the sea. On a certain day twenty years ago, the two islands collided, and the door between the earth and Tirano, another world, was opened. Automation; elves orcs, magic secrets, occultism and gods... Science and magic are intertwined and fused, conflicting but harmonious, converging but parallel. Twenty years later, Su Qi, who was entangled by nameless and invisible monsters, came to the sky under.