"Yuki Yuna is a Hero" is a Japanese anime series that follows a group of middle school girls who are part of a magical girl organization. They are tasked with protecting their world from mysterious creatures known as Vertex. The story explores themes of friendship, bravery, and sacrifice as the girls face various challenges in their heroic roles. The main character, Yuki Yuna, along with her friends Togo Mimori, Inubouzaki Fuu, and Nogi Sonoko, must balance their everyday lives with their responsibilities as heroes. As they fight against the Vertex, they discover the true nature of their powers and the consequences of their actions, leading to emotional and dramatic moments throughout the series.