An unremarkable office lady who spends all her time playing games finds herself possessed and reincarnated as Diana, the villainess of the otome game "Fairy Tale of Reminiscence." Immediately after her rebirth, she is condemned for a crime she has no memory of committing and is inexplicably exiled to a "dungeon." To keep watch over the villainess, Gray—one of the game's romanceable targets and an assassin—accompanies her. The two agree to cooperate in order to conquer the dungeon, but what awaits them inside are slippery tentacles straight out of an erotic game. Could this place actually be an erotic trap dungeon? As the traps grow more extreme, the distance between the two gradually shrinks, and their feelings for each other begin to waver in this tantalizing tale.