The film focuses on the lives of a variety of characters who happen to live in a rubbish dump. The first to be introduced is a mentally challenged boy who lives in a world of fantasy in which he is a tram conductor. He is both the tram and the tram driver and follows a set route and schedule through the dump; his dedication to the fantasy is fanatical. The film title refers to a Japanese onomatopoeia for the sound made by a tram or train while in motion ( "Do-desu-ka-den do-desu-ka-den do-desu-ka-den"). The sound is made by the boy as he makes his daily faux-tram route through the dump