An eerie, unnatural silence engulfed the whole world, and only the singing of nonexistent birds continued to flow out of nowhere. Not a soul had been seen for days...

Today, on an empty main street of a dead metropolis, you see a young girl. Hearing your approaching footsteps, the mysterious stranger slowly turns towards you; she smiles serenely with unreasonable warmth. Though her lips barely move, a melodious voice rings in your ears:

"Ah, a living thing!.. How unexpected.~♪"