The four of them are collectively known as Knight X. Until middle school, Knight X were the popular kids. However, because they were too handsome and got way too much attention, they decided to live as social outcasts (introverts) starting from high school. But when they realize that you are being bullied because of their introverted act, they decide to start coming to school as their true selves. By the way, since they spent their high school days looking down at the floor, no one besides Guest and themselves has ever seen their real faces.