The UK series Dragon's Den was adapted from the Japanese television programme Money Tigers.
Money Tigers, known in Japan as Money no Tora, established the central format: entrepreneurs present business proposals to several financially successful investors and seek funding. The investors can question the proposal, negotiate terms or refuse to participate.
The concept travelled internationally and was adapted for broadcasters in multiple countries. In the United Kingdom, the BBC used the title Dragon's Den and called its investors dragons, creating a distinct local identity while retaining the core pitch format.
Shark Tank is a separate American adaptation of the same broad international format, not the direct Japanese title behind the UK programme. The similarity between the shows is why viewers sometimes identify Shark Tank as the source, but Money Tigers is the specific predecessor credited for the format.