With the sudden appearance of the ons, the world had coirls with the power of the dragons, called “D”, were born within the human race The secret existence of the only male “D”, the boy Mononobe Yuu, was forcefully thrown into the school where the girls of “D” gathered – Midgard, where he saw the naked body of one of the students, IrisFurther lost sister Mitsuki, Yuu seems to have been enrolled into this school…!? “When there’s really no other choice, Iris, I will—kill you” “Can I really… believe you?” The curtains open as the “one and only story” about the boy as supposed to becoirl unfolds—! Unlimited School Battle Action!—–A 3 chapter prequel side story was released alongside some of the anime blu-rays titled ‘Unli on the Brynhildr class prior to the start of the main series