People on Campus: Forced to Participate in the Knight War

After Xu Yi, who was studying at Ayami City's Meitoku High School, spent an ordinary 17 years in this world, the new transfer student who arrived in early September of his sophomore year broke everything in this school... Xu Yi was involved in a knight's war while being chased by a mirror monster. He became a Kamen Rider and survived in this knight's war... Setting: (Mirrors can reflect people's nature. They live in the world in the mirror: "Mirror World". Mirror monsters that occasionally attack and prey on humans. Knights use card sets to sign contracts with specific mirror monsters to use their abilities.)