Character interactions done right. Be it romantic interactions or regular character interactions, it feels like they're actually alive, even if a lot of aspects of the story is very much fictional and wish-fulfillment kind.
I can't believe that a harem story could have this good romantic interaction between the MC and female lead(s), mostly Toga, the main girl. The interactions between her and the MC elevates the story a lot and endeared me to the pairing than any other fic here.
The only reason I can't give a full score is the update stability, but even that is not much of a weakness. Good things that are done right takes time, and this fic shows that those time are used very well. My only complaint is that I can't read more of this good stuff, but that's just because I like it that much.