Terutomo, whose father was killed by the mysterious organization Gungnir, continues his journey to collect the 99 "Devil's Keys" using the words his father left behind as clues in order to destroy them all. A mysterious brother and sister appear before Terutomo and become his new enemies. The brother and sister run a religious organization, and the sister has the power to read people's minds. And the 99th key is held by his father's enemy, Houshin. Terutomo takes on the new ACMA:GAME with his best friends Hajime and Yuki, as well as his new allies Sen'ya and Murasaki. In "Five Spell Survival," players choose their favorite ability with five letters and shoot the opponent's target. In "Down True or False," players ride a car loaded with explosives. In "The Gladiator," a survival game set in the deepest part of an ancient ruin, the birthplace of the "Devil's Key," the game develops into a final battle for the survival of humanity.