Hagure Yuusha no Aesthetica

Synopsis

The student council orders Kuzuha, as the class representative, to keep watch over Akatsuki and report his actions to them. It turns out that she is concerned about going to school with students so much older than she is. Akatsuki cheers her up and tells her to do as the student council has asked, since it will not deter him in the slightest. Later, during combat practice, the students find that their foe, a low level cockatrice, has been tampered with and is now too powerful to handle.

(Source: Wikipedia)