Bo-taoshi (Japanese: 棒倒し, Hepburn: bōtaoshi, "pole toppling"), is a capture-the-flag-like game, played on sports days at schools in Japan. The game, traditionally played by cadets at the National Defense Academy (NDA) of Japan on its anniversary, is famous for its size, wherein two teams totalling 150 individuals each vie for control of a single large pole. Each team is split into two groups of 75 attackers and 75 defenders. The defenders begin in a defensive orientation respective to their pole, while the attackers assume position some measure away from the other team's pole. A team concedes if its pole is brought lower than 30° to the horizontal (beginning perpendicular, or 90°, to the horizontal). Until a rule-change in 1973, the pole had only to be brought lower than 45° to the horizontal.
National Defense Academy of Japan official website. Regular Annual Events. This source is the National Defense Academy of Japan's official website. It contains schedules, classes, professors, activities, traditions, and sporting events. Bo-taoshi is traditionally played on November 1 which is also Self Defense Forces Day.