A juvenile delinquent code-named Saki Asamiya is taken in by the government and forced to fight crime to redeem her actions. She is sent to various high schools to infiltrate and neutralize gangs and other forms of crime as a police officer using her metal yo-yo badge as a weapon.

Kon Ichikawa's war film depicts the 60-hour period from the departure of the battleship Yamato, the pride of the Japanese Navy, until its sinking by the American forces during Operation Ten-Go.