Yuki shows potential but fails to deliver results, so Coach Sakurai calls in "Nao," a former protégée who has become a world-class anal prima donna. Together, the two women subject Yuki to a complete training regimen designed to master anal techniques, including anal hook insertion, anal stretching, enemas, and double penetration. Through this intense instruction, Yuki learns to fully utilize her anal depths, pushing past her limits and breaking into new realms of sensation.