VOID: NO. NINE - 9-BANME NO UTSURO

Void: No. Nine - 9-banme no Utsuro summary:

300 years ago, God destroyed the old world and killed humans, leaving only the "messenger".
But within underground, humans live in the tunnel-filled Reform City, humans still live underground. They search for relics, while living in fear from the threat of being hunted by the "messenger".
(Source: Anime News Network, edited)

300 years ago, God destroyed the old world and killed humans, leaving only the messenger.But within underground, humans live in the tunnel-filled Reform City, humans still live underground. They search for relics, while living in fear from the threat