I can see why this got a high rating of 9+. The characterization is great. MC has a clear goal to strive and develop to and the heroine is cool and breathtaking. She can speak her mind clearly while MC also isn't afraid to strive for his development early on in the series (not like other MC who takes more than a hundred chapter just to have some development). The interactions are complex and there are some intrinsic aspects between conversations so it adds a subtle depth to it. It's quite impressive to see a complex interactions without seeing unnecessary drama to fuel the complexity of it. I hope it stays like this and the author doesn't succumb to unnecessary drama.
Although this is slice of life/romance, the conversations feel rich and well written. 9.5/10 for me.