I really like this one. It's got a slow burn feel (three chapters in and the mc and ml aren't even remotely considering one another as love interests, just as interesting people) and it's got a great mc (seiichirou having an actual brain on his shoulders, he's an adult and acts like it even so far as to have everyone else be suspicious of him because he as an adult wants to look after and care for a minor). The characters are likable (well the ones we should like are), and it even has a good semblance of plot. I'm kinda glad this came as a novel first, I haven't read the translated chapters yet (I plan to), but this being a completed novel before being adapted feels really nice to me, as it has a set direction. Add in the fact that it's not a "super powered mc does magical setting stuff and the captain of the knights falls in love in a kind of superficial way!!" type plot and more of a "mc talented in [math??] wins the heart of the local knight captain by...doing his job???" I'm a sucker for those types of love plots. It seems like it'll be grounded enough that the fantasy elements will be easily digestable and not distracting. I'm looking forward to it and the path of slow burn romance (bc let's be real the mc will take his time falling in love)!
