Shashou is the conductor of the Galaxy Express 999, a mysterious and recurring character in Ginga Tetsudou 999. He serves as the train's calm, authoritative guide, helping passengers board, travel safely, and understand the rules of their interstellar journey. Often composed and formal, he acts as both caretaker and symbolic presence aboard the train. His role is central to the series' atmosphere, as he connects the adventures of the passengers with the larger themes of travel, destiny, and the passage through space.