Lots of people talk about helping others, but Yuna Yuki and her friends Mimori Togo, Fu, and Itsuki have gone a step further, forming a "Hero Club" that people can ask for assistance. Then things go further than they ever expected when they find themselves offered real super powers in exchange for helping defeat the Vertexes, who seek to destroy the Divine Tree and kill all life! It's an easy decision to make, but what they don't know is the price that each of them will have to pay for their new abilities. With great power comes great responsibility, but in this case it also comes with a devastating cost for every girl who enters the Hero System. Get ready for the genre-bending series that changed Magical Girl anime forever in the complete multi-series collection of YUKI YUNA IS A HERO!