The PSS heat-aware Imperial Palace running event is a low-key summer race in central Tokyo. It starts and finishes near the Clock Tower inside Sakuradamon Gate. Participants can choose from 5 km, 10 km, 20 km, or a 20 km relay. The longer events begin earlier in the morning, with the shorter races starting at 9:00. The entry fee is intentionally low: solo races are 1,000 yen, and the relay is 4,000 yen per team. The 5 km and 10 km races are open to all, the 20 km race requires participants to be 13 or older, and the relay is open to mixed or single-gender teams.
The course follows the Imperial Palace running loop, consisting of repeated laps. PSS describes it as Japan’s most relaxed race, allowing late arrivals, same-day entry, and distance changes on race day. If a runner stops early, they are recorded for the distance completed, not as a non-finisher. The organizer might even create an unofficial distance, like 15 km. All participants receive an award, with record sheets or certificates sent later. Participation gifts may include a sports drink, an izakaya meal ticket, and a timing chip. The event may be canceled due to weather or broader social disruption, with no refund but an indefinite transfer to a future race.