Seitarou Higuchi, Akashi, Ozu, and Ryouko Hanuki, a group of friends, exchange various anecdotes while discussing a bizarre idea of a submarine that can navigate through land. Each one tries to outdo the others by proposing unique concepts ranging from stopping the ice caps from melting to guarding women against voyeurs and even embarking on a fishing expedition. The discussion has no bounds, and they explore various topics.