It's very good. In some ways, you could say MC is OP, but definitely not in a boring sense as he does have troubles that somewhat balance them out. As of the first 100 chapters, there's no romance and I can't imagine seeing any for a while.
Idk about annoying flies if you mean annoying characters, or implying about annoying female characters (since that is what most action readers complain about in the reviews), but this series is one of the ones that treats its supporting cast pretty equally. The female characters aren't treated much differently from the male ones, being MC's classmates for the most part. They aren't sexualised (thank gods, I forget what age they are but I assume in their mid-to-late teens) and we even have a female character with big muscles! We also have a few other female characters who seem more androgynous, making people confused what pronouns to use for them, haha.
It's not perfect, but I definitely recommend giving this a read and see how you feel about it. I'd say to go in with an open mind (though this is my advice to any series).
Thank you~ you make me wanna pick this up now(≧∀≦)
Then. Do. It.
Can someone gimme some review about this one? Is mc op? Any romance? Are there some annoying fly? Any precaution?