htoL#NiQ: The Firefly Diary
In the depths of a labyrinthine ruin, a young girl named Mion awakens from a deep sleep. Lost, alone, and with no memory of how she got here or where her parents are, she is greeted by two fireflies - one that is all light and another that lurks in the shadows. Switching between the world of light and the world of shadow, the two fireflies must work together to recover Mion's memories and lead her out of the ruins, where ravenous shadow creatures, ancient machines, and treacherous traps lie in wait to block her path.
Story
The story begins on December 31, 9999, when a young girl named Mion wakes up with amnesia at the bottom of a dark ruin in a desolate world. Desiring to free Mion from the rubble and see the outside world, the firefly Hotaru leads her on a journey up through the ruins. On her journey out, she finds unmanned machines, disfigured vegetation, and the bodies of dead children.