Minamata disease was first officially recognized in May 1956. Its earliest victims were small children. Environmental contamination most rapidly and seriously affected the physiologically weak among the residents. However, the outbreak of the disease in humans was preceded by abnormalities in the natural environment such as massive death of fish and shellfish, and the abnormal behavior and death of cats. It used to be considered that poisoning was caused by direct exposure to a toxic substance, and that toxic substances did (...) not pass the placenta. Minamata disease is an indirect poisoning by methyl mercury through the food chain as a result of environmental contamination, and is the first known disease to cause abnomalities in the fetus due to a toxic agent passing through the placenta. Minamata disease, therefore, had implications in various fields. Namely it also stirred up legal, ethical, and eugenic arguments concerning fetal protection. This report reviews the course of Minamata disease, and evaluates its impacts. “Minamata Studies” has three intellectual and scientific missions to change the social systems that caused the disease; to pursue environmental justice; and to explore the possibility of an environment that permits coexistence not only of all humans, but of all living things. (shrink)