The Japanese business reality show that inspired the British series Dragon's Den is Money Tigers.
Money Tigers, known in Japan as Money no Tora, established the core format later adapted in many countries. Entrepreneurs present business plans to a panel of wealthy investors, hoping to secure capital in return for a share of the company.
The British adaptation began on BBC Two in 2005 and changed the investor nickname to “Dragons”. The basic dramatic structure remained recognisable: a formal pitch, detailed questioning, negotiation and the possibility of rejection.
Shark Tank is not the source programme. It is the American adaptation of the same broader format family. The title Money Tigers refers specifically to the Japanese programme that originated the concept used by Dragon's Den.