In a world where the concept of secondary genders such as alpha, beta, and omega does not exist, high school student Takai Shikito leads a quiet life. He is bookish, scientifically curious, and deliberately keeps a low profile, though he secretly admires his charismatic and popular classmate Nishio Ririto. One ordinary day, Takai notices an unusually alluring scent coming from Nishio. Later, during gym class, Nishio is overcome by a strange, feverish heat. Concerned, Takai attempts to escort him to the nurse’s office, but the two are drawn instead into a secluded gym storage room. There, driven by an overwhelming, unfamiliar instinct, they become physically intimate for the first time.

Neither boy understands what is happening to their bodies. Nishio’s heat does not subside, forcing him to remain hidden in the storage room for seven days. Takai brings food, supplies, and covers for their absence, all while his own body begins to change: his senses sharpen, his vision improves, a knot forms on his penis, and he feels a powerful urge to bite Nishio’s nape. The boys gradually realize they are experiencing something unprecedented. Drawing on his knowledge of animal behavior and biology, Takai suspects they are undergoing a phenomenon resembling a wolf pack’s bonding system. Nishio’s thoughts and emotions begin to transmit directly into Takai’s mind, forging a psychic link between them.

Nishio comes from a blended family; his mother remarried, and he quietly struggles with feelings of not truly belonging. Takai, the son of a doctor, is gentle and intellectually driven, but the alpha instincts awakening in him bring possessiveness, territoriality, and a fierce need to protect Nishio. The story follows their evolving relationship as they navigate the physical and emotional turmoil of being the world’s first alpha and omega, with no societal framework to guide them. Their seven-day confinement in the storage room becomes a crucible where instinct, vulnerability, and affection converge.

The narrative later expands beyond that initial week. As they return to school life, Takai and Nishio must manage their ongoing bond—the periodic heats, the telepathic connection, and the social pressures of hiding their condition. Their families, friendships, and futures are all affected as they become the inadvertent pioneers of a new stage in human evolution. The series traces their growth from confused teenagers into a pair who, despite the absence of any divine blueprint, build their own Eden together.