Lily in the Gravity Labyrinth

is a Japanese light novel series written by Tobisachi Kaneko, with illustrations by Yasutaka Isegawa. The series began publication on May 9, 2015 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
If you look up, this is an underground city covered with a canopy. The bottom where only scraps exist. The city, lined with obscene buildings and surrounded by strange heat, is called the "Labyrinth Formation".

Born and raised in such a slum, Chunk's livelihood is to search for and kill the mechanical beast cannibal that springs up in the suburbs. It was the worst environment, but Chunk liked the simple life. Neat's older brother Sout, a genius who uses computers and withdraws.

Cannibal hunting friend Dust Bunny. Nero, the information store of the guardian. Misirlou, a girl from the Mafia private army group "Angel Corps". Chunk's daily life surrounded by weirdos, however, changes one day. Lily, a mysterious girl he picked up while hunting. That was the beginning of a major event that shook the underground world.