The protagonist, Ren Homura, returns to the town of Kaminohara, where he once lived. But did he really live in this place before? A nagging feeling tugs at his memories. Meanwhile, a strange game is forcefully installed onto his smartphone - a game called Monster Strike. A gauntlet of battles await him. Through the fierce fighting, he pieces together his scattered memories while uncovering the truth of the game. He's supported by his companions: Aoi Mizusawa, Akira Kagetsuki, and Minami Wakaba. Together they take a step into the unknown, unsuspecting of the secrets hidden below the surface...