A girl suddenly vanishes from her world and finds herself drifting in and out of consciousness in a world of pure darkness. The only insight into her precarious situation is a prompt opening before her eyes indicating that the system failed to delete her.The doggedly optimistic and naive teenager, Naomi, is reborn as a monster into a fantastical world governed by the rigid rules of a suspiciously game-like system; a world full of magic and danger where the familiar mingles with the inexplicable. She finds herself deep in the bizzarre, savage forests of the unclaimed lands where deadly monsters prowl in the shadows just out of sight.After a close brush with death, any hope that this could be a lighthearted adventure evaporates as she feels real pain for the first time. The realization sinks in as Naomi comes to terms with this not being just a game; it’s her reality now.As if coming to grips with the life or death survival situation she finds herself in isn’t enough, the description of one of her skills seems to be speaking to her...

She became a dungeon core.

Everything pointed Delta to murdering her way to success. People were just mana farms, right?

No, that was wrong. Delta refused. Then everything became odd.