(W/A/CA) Akihito Tukushi Riko and crew have encountered a mysterious cave raider squad in the depths' sixth layer! When they join them at their hideout, they find Srajo, the Sovereign of Mystery, awaiting them with a trial! Can they overcome her challenge and win her trust?

(W/A/CA) Akihito Tukushi In an age when the corners of the world have been scoured for their secrets, only one place remains unexplored-a massive cave system known as the Abyss, filled with monstrous creatures and lost relics. Those who delve into its depths are known as Cave Raiders. A young orphan named Riko dreams of following in her mother's footsteps as a Cave Raider, and when she meets a strange robot while exploring the Abyss, she is one perilous step closer to achieving her goal!