Why it's licensed
Certain parts of the pufferfish contain a potent toxin, and in Japan only chefs who have completed a specific licensing process are legally permitted to prepare and serve it — a serious, multi-year qualification rather than a formality. Eating fugu at a licensed restaurant is considered entirely safe; the danger associated with the fish is precisely why the preparation is so tightly controlled.
Osaka's fugu tradition
Osaka is one of Japan's largest fugu wholesale markets and has a long-standing local dining tradition built around the fish, often served as thinly sliced sashimi (fugu-sashi) arranged in a translucent, almost decorative pattern, alongside hot pot (fugu-chiri) in colder months.
What to expect at a meal
A proper fugu course typically moves through several preparations of the same fish across a meal — sashimi, grilled fin served in hot sake (hire-zake), a hot pot, and often a rice porridge made from the pot's remaining broth at the end. It's a slower, more ceremonial meal than most Osaka dining, and priced accordingly at dedicated fugu restaurants.
Only order fugu at an established, licensed restaurant — this isn't a dish to seek out from an unlicensed or informal source under any circumstances.