Fugu is the Japanese word for pufferfish and is also a Japanese dish prepared from the meat of pufferfish (normally species of Takifugu, Lagocephalus, or Sphoeroides) or porcupinefish of the genus Diodon. Because pufferfish is lethally poisonous if prepared incorrectly, fugu has become one of the most celebrated and notorious dishes in Japanese cuisine.

Fugu contains lethal amounts of the poison tetrodotoxin in the organs, especially the liver and ovaries, and also the skin. The poison, a sodium channel blocker, paralyzes the muscles while the victim stays fully conscious, and eventually dies from asphyxiation. Currently, there is no known antidote, and the standard medical approach is to try to support the respiratory and circulatory system until the poison wears off.

As of 2008, advances in fugu research and farming have allowed some farmers to mass produce non-toxic fugu. Researchers surmised that fugu’s tetrodotoxin came from eating other animals that had the tetrodotoxin-laden bacteria, and developed immunity over time. Many farmers now are producing ‘poison-free’ fugu by keeping the fugu away from tetrodotoxin-laden bacteria. Utsuki, a town in Oita, became famous for selling non-poisonous fugu. No one has been poisoned eating it.

Fugu has been consumed in Japan for centuries, although its historic origins are unclear. Bones of fugu have been found in several shell mounds called kaizuka in J?mon period that date back more than 2,300 years. The Tokugawa shogunate (1603–1868) prohibited the consumption of fugu in Edo and its area of influence, yet it became common again as the power of the shogunate weakened. In Western regions of Japan, where the influence of the government was weaker and fugu was easier to get, various cooking methods were developed to safely eat these fish. During the Meiji Era (1867–1912), fugu was again banned in many areas of Japan. Fugu is also the only delicacy officially forbidden to the Emperor of Japan, for his own safety.