Ayako Saito, a skilled dancer and Assassin nicknamed as Blood's Rythym or DANCING ASSASSIN. She can be a very bright and immature girl but can be dark and mature when needed or triggered. She can be quick in her toes and kill a person with one swipe. With her skills, she can lure thousands of people in her trap. With that, the government decided to make her join the Class E and kill a yellow octopus that destroyed 70% of the moon with Mach 20 speed. However, she meets the sadistic character in her class. She found him interesting and tried learning more about him. But will she ever kill the octopus with the sadistic one come March?