Professor Asakichi Iwaya, also referred to as Iwatani in some sources, is a scholar residing in 1964 Tokyo with expertise in Ancient Greek studies. He encounters Demetrios after the young Greek man unexpectedly appears in Tokyo following a lightning strike. Despite initial language barriers and cultural confusion, he accommodates Demetrios, interpreting his unusual appearance and behavior as harmless foreignness. His academic background allows him to recognize elements of ancient Greek culture in Demetrios' actions and knowledge, though the young man's sudden appearances and disappearances remain surprising.

His interactions extend beyond shelter, guiding Demetrios through modern concepts and historical events. He takes Demetrios to a cinema where he recounts the historical impact of World War II, including the cancellation of the 1940 Tokyo Olympics and its broader global consequences. This moment provides Demetrios with a deeper understanding of modern history and the significance of peaceful international events like the Olympics.

His role bridges eras through cultural exchange. Demetrios carries knowledge of modern sports and customs back to ancient Greece after encountering them in 1964 Tokyo, indirectly influencing events in Tritonia. Conversely, his observations of Demetrios' ancient Greek habits and perspectives contribute to his own studies.

In the concluding events, Demetrios is unexpectedly transported back to 1964 Tokyo moments before a significant personal moment in ancient Greece. This results in an accidental kiss between Demetrios and him, occurring shortly before Demetrios learns about an altered future outcome of the Olympics he helped organize. His presence during this unintended return underscores the ongoing connection between the two characters across time periods. His character remains focused on his academic perspective and his role as an anchor for Demetrios during the temporal disruptions.