A college student and his friends—Seitarou Higuchi, Akashi, Ozu, and Ryouko Hanuki—share various stories about a submarine that can travel through land, each one trying to outdo the others in terms of creativity. Ranging from a journey to stop the melting of the ice caps, to a quest to stop perverts from spying on girls, and to a fishing trip, no topic is off-limits.