I found fighting, animation quality and ecchi scenes are worthy of complementing.
But mc is a masochist. I hate the concept of slavery. Jobless mc with the uncertainty of getting a job accepts to become the girl's slave by giving up his honour and pride and dreams of becoming a delusional Hero. Even the girl depends on him she refers him as a slave in the whole anime(specially in the 1st season). She never tries to recruit him in the battalion even when he increases her strength.
I hate the basic concept but liked other parts of the story.