In the near future, household pests like cockroaches have developed an immunity to insecticides. To address this issue, a Japanese company has created cute, doll-sized robots called Hoi Hoi-san to exterminate insects. Another company has also released a competing product called Combat-san. These robots have gained a huge following due to their adorable appearance. In one household, a fan of these robots uses Hoi Hoi-san and Combat-san to search for insects at night. However, Combat-san is not above attempting to exterminate Hoi Hoi-san in the process.