Yuuki Yuuna wa Yuushabu Shozoku 3
Yuuki Yuuna is a Hero Club Member 3
Washio Sumi wa Yuusha de Aru
結城友奈は勇者部所属
The story takes place 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."
(Source: ANN)