Heine (voiced by Keisuke Ueda) has a small body and cute appearance. As a completely ordinary person, he has neither a prominent family background nor any higher education, but he was unexpectedly selected to become a "royal tutor". His task is to select plastic talents from four princes with different personalities and train them to become candidates for the throne. Reinhardt (voiced by Daisuke Hirose), who has a more beautiful appearance than a woman but lives in deep inferiority, Bruno (voiced by Yuto Adachi), who is full of poetry and books and has a stubborn and extreme personality, Richter (voiced by Shota Aoi), who is cheerful, optimistic and approachable, and Kai (voiced by Yuya Asato), who looks cold and unapproachable but actually likes cute things. What kind of problems will these bear princes who don't obey discipline give Heine?