Set in a world where history has taken a slightly different course from the one we're familiar with, K follows the story of a young boy whose life is caught in a psychic war between seven kings. Ashinaka High School is known for its unique setting: the entire campus is built on an island. Yashiro Isana, aka Shiro, is having lunch with a cat on one of the school rooftops. After his lunch break, Shiro goes on an errand for his classmate Kukuri to prepare for their upcoming school festival, only to be chased by some intimidating-looking men.