Class 1-A takes a field trip to Yokohama, the once city of Japan, now an isolated and independent country which is said to be full of criminals and quirkless people. Staying under the protection of the Armed Detective Agency, these up and coming heroes will see how the city really is. No heroes, no villains, and no clear line between what or who is good or bad. Will their morals and views change as they stay in the city? What is good? What is bad? Who is truly evil? Yokohama is a gray area, there is no side that is perfectly good or perfectly evil.