38th Asahi City Iioka Shiosai Marathon Chiba 2027

The 38th Asahi City Iioka Shiosai Marathon returns to coastal Chiba Prefecture on 7 February 2027. Despite its traditional name, the longest distance is a half marathon. This established local festival combines a flat, seaside road course with winter views of the Kujukuri shoreline. The previous edition attracted 2,813 entrants.

Course and schedule

All distances start near Hagizono Park and finish at Shiosai Stadium. The coastal out-and-back course is generally level, although sea breezes can affect pacing. Runners must keep left and follow their assigned start blocks.

The opening ceremony is at 08:00 JST. The primary-school 3K starts at 08:50 (boys) and 08:53 (girls), followed by the parent-child 2K at 09:25, the 5K at 09:50 and the half marathon at 10:45. Time limits are 25 minutes, 20 minutes, 45 minutes and 2 hours 50 minutes respectively. The 5K checkpoint closes at 10:35 (4.6 km); the half-marathon checkpoint closes at 13:25 (20 km).

Runner logistics

The event is known for local strawberry refreshments, complimentary pork soup and sweet red-bean soup, and a friendly community atmosphere. Olympic marathon champion Mizuki Noguchi and the Nitori women's running team are announced as 2027 guests.

Bibs and timing chips are mailed in late January, so there is no race-morning registration desk. Changing rooms and paid baggage storage are at the Iioka Utopia Centre. Free shuttles operate from JR Asahi Station and designated car parks. Coastal parking cannot be entered or exited from 08:30 to 13:40. The race proceeds in rain unless conditions are unsafe; the organiser's entry terms exclude cancellation refunds.