Yuusha and his harem.
I imagine this could be a much better anime if the storyline is told with a lot more details. Can’t help to think that so many important details were left out, leaving us some confusion and very shallow impression about the war itself. Seems like this anime just jump around to any point they feel like it, and we have to use our own imagination in guessing what happened in between. Instead of showing us more about the setting, I would say they spend more-than-necessary time to show us how Yuusha build his harem.