The Japanese television format that inspired Dragon's Den is titled Money Tigers in English.
Money Tigers was created by Nippon Television and became the source format for a number of international versions. In the original concept, entrepreneurs seek financial backing by presenting their business ideas to a group of wealthy investors. The UK adaptation retained this basic face-to-face negotiation structure while calling its investors “dragons.”
The format travelled widely because the rules are easy to understand but produce unpredictable negotiations. Each entrepreneur must state the amount requested and the ownership share offered, after which investors may ask questions, compete with one another, or decline to participate.
Money Tigers is often confused with Shark Tank, the later American adaptation that uses a different title and investor nickname. Dragon's Den is not an unrelated British invention: it is one of the international adaptations of the Japanese format.