Monsters are woven into everyday life now, and Ren, Aoi, Akira, and Minami have made it their mission to protect their neighborhood from the ones that turn violent. Things change when Mana Livingston transfers into their class from America. She befriends the group, learns about the Monster Strike game, and gains a ring and a monster partner of her own. Together they deal with crises caused by energy points that pull monsters into random parts of Japan, sealing each one so the monsters stop gathering there. Madarame, a company CEO, approaches the children, but he is keeping part of the truth from them, and a shadow of coming danger starts to grow. This second season of the fantasy action ONA is animated entirely in CG and runs 24 episodes, counting an episode 0.