Okay, I enjoyed this a bit. I have some gripes but it was definitely solid and worth the time investment.
First off, he ended up with the model. It’s not open, it’s right there in this chapter.
I agree that the relationship with the teacher is glossed over way too much. There’s a lot of implied going on in their relationship. I honestly thought they just kissed, even with the take responsibility comment, until the panel where you see them kissing naked or in their underwear. Whichever it was. There was enough written and shown from outside conversations, especially from the short haired teacher, but not enough from the MC showing he had that sort of feelings to leave the impact. Obviously it was there to juxtapose with the other relationships in the story. I think namely the one between the two who got married in the end as well as Mc and the model. I can’t remember any names so forgive me.
Speaking of the married couple, now that was good progression. By far the most satisfying romance of the manga. It’s honestly odd that the author fleshed out their romance more than the MC with the teacher, the model, and the girl hiding her intelligence (who keeps denying her feelings and they don’t end up together but it’s definitely implied she felt something beyond appreciation and admiration). Not just that, but the married girl was truly the best girl in the manga, yes? Like it wasn’t even close. If they focused a tad more on the old teacher guy you would think this was about them and not the geniuses.
All in all it was good. There was a lot for the reader to assume about. The above mentioned and some of the other stuff like the model initially falling for Mc, the backstories of the girls, etc. Not everything spelled out like we’re morons. On one hand it can get a little confusing tbh. Maybe I am a moron. On the other it goes right in line with the theme of this manga. Right? For better or worse, it’s different in that regard and I can appreciate an author not treating the readers like they are too dumb to understand every little sentence.
Solid 7.5 imo. Could have benefitted from another 5 or so chapters.
ETA they focused too much on the siblings to not give proper closure. Unless I’m forgetting the brother sort of got it with acceptance when the MC replied with his own program or whatever. But the sister’s reappearance was basically only to invoke the the relationship between the MC and the teacher more. But again, that got enough from the supporting characters. It needed more fleshing out from the two (mostly just the MC) in the actual relationship.