It's a 2009 anime adaptation of a 2007-2013 light novel series. Don't go looking for an anime version of the later volumes that didn't get adapted here. That doesn't exist. The title character (Luke Ainsworth) is a blacksmith who can make a sword in about thirty seconds (with demonic help) but has the manners of a grumpy sewer rat. The protagonist (Cecily Campbell) recently became a knight after her father's death and she's admirably brave and honourable, but she's not very good at her new job (yet), can't even fight, doesn't believe in killing and doesn't understand politics.
The setting and backstory are important. Cecily is a knight in Housman, the Third City of the Independent Trade Cities, which in geopolitical terms is small and weak. Its neighbours include an Empire and a military dictatorship. There's also a superweapon (Demon Contracts) that's been banned for 44 years, since the Valbanill War. Further secrets are in ep.10.
This is quite a serious show. It has fanservice and light-hearted moments, but not the ironic distance and self-commentary of some isekai stories. It's inhabiting its world properly. The cast all have issues and dramatic motivation. I quite like where the story's going.
That said, though, the anime's better in the second half. The turning point is ep.6, when the high-handed Charlotte E. Firobisher appears and tries being snotty to Luke, which is funny because he's a bigger dick than she could ever be. Suddenly, the series finds a new level of emotional weight. Until then, we'd been stuck with Cecily and Luke. The girls I liked. Luke is a pain in the arse. He has a tragic past, obviously, and it'll be possible to empathise with him once that's been revealed. (Sort of. Through Lisa.) I'd still disliked him in those early episodes, though.
Cecily's knight outfit is silly. She wears:
(a) a breastplate that's been moulded perfectly to her bosom. It's like a metal sports bra and only covers her ribcage, i.e. the bone cage that's actually quite good at protecting your squishy bits. She wears no armour on much more vulnerable areas like her legs, belly, etc.
(b) a useful-looking metal shoulder guard.
(c) leather gloves and boots, plus metal shoes
(d) a frilly skirt
(e) a body stocking
This looks plausible at first glance, despite the way it highlights her boobs, but it becomes a joke if you think about it. Bizarrely, in ep.9, Cecily's friends and family think she could improve her sex appeal by wearing a dress (which she hates). She also goes topless in a few episodes.
I ended up quite respecting this series, but I won't rewatch it and I've ditched the episodes. There's still plenty to admire here, though, e.g. the author's historical research. Someone uses a bollock dagger, for instance. (That was a real medieval weapon, named for the shape of its hand guard and for the place people tended to wear it. The Victorians renamed it a "kidney dagger".) You could do a lot worse than this show, but don't expect to like Luke for a long while.