The setting this time is the UA dormitory right before the Endeavor Internship arc of season 5! In the dead of winter, a cold and stormy battle is unfolding in the Heights Alliance! Third-year Mirio Togata suddenly appears when the first-year students of Class A are bored during the ban on going outside. She brings with her the card game "Yuuei Heroes Battle", created by the support class. As each student chooses cards and joins the fierce battle, there appears to be more to the game than meets the eye. In the end, who will emerge victorious?