It has a harem tag, because of that other female that the mc met in the story. The nobles daughter. That is clearly in love with the mc. But couldn't go with the mc, because of her noble duties. And there's hints that the father, is setting up something with the mc. So she could end up being a potential love interest. But that's something down the line, story wise. Not sure if there's other female characters even later in the story. That are interested in the mc. Because i haven't read the source material of it.
Read the web novel a few years ago; about 100 chapters. Started ok, felt like it became more of a slog to read later. I feel like many Japanese fantasy series start with a decent twist but ultimately become more generic as the story progresses. Yes, the harem tag is warranted. After the climax of the arc with the antagonist, lets just say there were a lot of girls who wanted to get to know mc better. Didn't read anymore after that. I felt that introducing more and more female characters without really exploring the current female characters made it feel incredibly vapid. (At least I remember most of the female characters not having much character, correct me if I'm wrong). It seemed to be leading to another arc after that but I had already dropped it at that point. I've seen the "mc inadvertently ruins the 'other characters' plans" stuff before but this one fell short compared to others imo.
