In the future, after the latest World War, various nations of the Earth joined forces and built a super-powerful computer knows as "Juno", which would be able to preserve peace and to help scientists in their researches. Every four years, a fighting tournament is held by the company that built the computer. The rules of the tournament are strange: female fighters who lose agree to perform services of sexual nature. The Time and Space Investigation office decides to find out what really happens there, and sends a young employee named Hayate to participate in the tournament...

Jikuu Sasatsukan Hayate: Inspector is a one-on-one fighting game. There is an exercise mode, but it only allows to fight one opponent on an easier difficulty level. In the "normal mode", the difficulty is higher, and all the fights are dictated by the story; it's impossible to choose player-controlled fighters, opponents, scenario, etc. Every battle has just one round. The fighters can use various punches and kicks, jump, and execute powerful special attacks, which deplete their "spirit bars". Scenes with nudity appear between the fights.