The British series Dragon's Den is based on the Japanese business-investment programme Money Tigers.
Money Tigers was a Japanese television format in which entrepreneurs presented business ideas to wealthy investors and sought funding in exchange for a share of their company. That central negotiation model was adapted for international television, including the British version broadcast by the BBC.
The British programme keeps the essential structure: a founder enters the room, gives a pitch, answers questions about the business and then hears offers from the investors. The Dragons can also negotiate ownership percentages, reject the proposal or make competing offers.
A common mix-up is to identify Shark Tank as the source. Shark Tank is the United States adaptation of the same broad format and uses sharks rather than dragons as its investor nickname. The format itself traces back to Japan, while the British title and terminology were adapted for the United Kingdom.