Yuuki Yuuna Wa Yuusha-bu Shozoku結城友奈は勇者部所属; Yuuki Yuuna is a Hero Club Member; Yuuki Yuuna wa Yuushabu Shozoku

In the era of the gods, year 300. Yuuna Yuuki lives an ordinary life as a second year middle school student, but she's also a member of the "Hero Club," where club activities involve dealing with a mysterious being called "Vertex." - ANN