The original Japanese television format that inspired the British series Dragon's Den was called Money Tigers.
Money Tigers was a Japanese programme in which entrepreneurs presented business proposals to wealthy investors. The central idea was later adapted for several national markets, with the investors receiving different names and the title being localised for each audience. In the United Kingdom, the investors became Dragons, producing the title Dragon's Den.
The concept is often confused with Shark Tank because both programmes use a panel of investors and entrepreneur pitches. Shark Tank is an American adaptation in the same broad franchise family, not the Japanese title from which the British version directly developed.
The Japanese origin explains why the British programme has a recognisable international structure while retaining specifically British presentation, terminology and investors. The adaptation model also allowed versions to appear in numerous countries, each using a culturally familiar name for its panel of business people.