Haruki Komaba, an ordinary high school student, becomes the focal point of a heated conflict between classmates Airi Kuze and Ayana Hizuki. Airi, a half-cyborg, leads the Mechanical Science Club, while Ayana, a part-canine experiment, commands the Chemical Science Club. Both vie for his romantic attention and club membership, resulting in Haruki’s accidental dual promise to join their clubs and his entanglement in their rivalry.

His encounters with Airi and Ayana spiral into ecchi mishaps, frequently amplified by Ayana’s older sister Touko Hizuki. Intervening for Ayana, Touko deploys sexually charged chemical concoctions that intensify the chaos. These incidents arise from Ayana’s experimental errors or Touko’s scheming, leaving Haruki perpetually caught in their explosive crossfire.