Shinobu, son of Sou Shirokane, president of Wahre Liebe Pharmaceutical Company, ponders whether he would prefer not to be reborn as a mouse if it meant being subjected to experiments. There are rumors within the company that 40% of its drugs were developed by Shinobu, who is considered a genius.
After Shinobus mother dies suddenly, Sou begs Shinobu to use his powers to resurrect her. Taking pity on the lab rats, Shinobu injects the mahou shouj