Previously, Saki's departure from school was to swap her uniform with prison attire. However, the Federal authorities sought out Saki to go undercover and infiltrate a merciless criminal outfit in an elite high school. They opted for the toughest bad girl around. Saki is now out on the streets, possessing classified equipment that resembles a yo-yo, and authorized to utilize any means required to accomplish her mission. Beautiful yet deadly, Saki is prepared to endanger everything, knowing that if she flounders, she will be dressed in a shroud.