In a near-future Japan where climate collapse has accelerated the mutation of insect life, a parasitic wasp species known as the Jinmen-mushi begins infecting humans, transforming them into grotesque human-insect chimeras driven by a collective hive intelligence. The story follows high school student Ryo Aiba, who awakens after a Jinmen-mushi attack to find that he has partially merged with the parasite yet retained his human consciousness. He gains the ability to sense the hive’s impulses and control fragments of its swarms, but he is neither fully human nor fully monster. Alongside a clandestine government unit called the Extermination Division, which deploys genetically modified predatory insects to hunt infected hosts, Ryo struggles to contain the outbreak while searching for a cure. The central conflict pivots on the Jinmen-mushi queen, a colossal gestalt entity buried beneath Tokyo, which is slowly rewriting the genetic code of all infected to remake the planet as an insect-dominated ecosystem. Major narrative arcs include Ryo’s flight from the division’s order to kill him, his uneasy alliance with a rogue scientist who created the Jinmen-mushi as a bioweapon, and a siege arc where the hive overruns the city’s last fortified dome. A later arc delves into the queen’s memory, revealing that the infection is a retaliatory response to human pesticide bombardment of ancient insect colonies. The series culminates in Ryo’s choice to either merge fully with the queen to negotiate a ceasefire or unleash a counter-parasite that would exterminate both the hive and all partially infected humans like himself.