Ranmaru Tomonaga, Hikaru Kamekanbo. and Kanji Miyazawa, who happened to meet through a strange turn of events, ride in a car to eat and sleep at hot spring inns as they journey across Japan to find an enigmatic hot spring geisha called Miyabi.

Ranmaru Tomonaga may be a bit naive and dorky, but he's got something of an endearing quality that is hard to dislike. Above all, he has a tongue like a gas-chromatography device, capable of analyzing whatever it comes in contact with. Sure enough, that tongue leads him into all kinds of trouble as he gets embroiled in solving one puzzling mystery after another. Along the way, he picks up a suspense drama fan girl named Hikaru Kamekanbo. They meet up with Kanji Miyazawa, a straight-laced man who is the only person capable of reining in the quirky pair and keeping them out of trouble. The three of them become traveling companions, traversing the countryside in a beat-up automobile, sleeping and eating in some of the nation's best-kept secret hot springs, and searching for the mysterious geisha "Miyabi" in a comical mystery adventure.