The KITA!SENJU Marathon takes place on the Arakawa River in Tokyo's Adachi ward, centered at Niji-no-Hiroba. It occurs in late June, beginning at 8:15 a.m. The event offers multiple distance options: 1 km (for children up to elementary school age), 3 km (for students up to junior high school age), 5 km, 10 km, 15 km, a half marathon, and a 20 km relay.
The course follows the Arakawa riverbank, featuring open paths. Participants can choose from 5 km up to the half marathon. Students have access to separate, more affordable race categories across several distances. The 20 km relay includes team competition with male, female, and mixed divisions for general participants and high school teams.