Giving a 10 to all the categories feels ridiculous even to me, but I had to be honest with the ratings and those are my honest feelings about this series: the plot is excellent, the acting is excellent, the music is excellent, and the characters are memorable and very easy to grow fond of, even the support roles.
This series is not the kind that leaves you completely mind-blown, nor a cinematic masterpiece. What I believe makes it earn its score is how everything was taken care of extremely well, from the plot to the characterization to the various themes in the story.

Starting from the plot: it's very good. Since I've read and watched many (MANY) love stories with similar premises and tropes, I tried to guess the events and the conflicts from the very beginning, so you can imagine my surprise when the story just kept surprising me at every single turn - and I mean it in the best way possible.
If you've watched some series before, you might have felt frustrated by the plot for one reason or another: maybe because the main characters didn't communicate properly with each other, or because of silly decisions, or because of characters being annoyingly naïve or clueless, or even just because of tropes that were placed there to bring conflict and troubles. Sometimes I even start arguing with the screen when that happens.
Whoever wrote My School President probably finds them annoying and frustrating too, because there is none of that in the entire series. The plot flows nicely without obstacles that have no reason to be there other than to make things dramatic. This series is also the proof that you don't need any of that to make a story interesting, because I was almost unable to take away my eyes from the screen until I finished watching all the episodes. And I didn't argue with the screen (or felt the need to) even once.
I also believe that the mood of all the scenes was handled perfectly. The cute scenes are actually cute without feeling embarrassing or too mild, the funny moments are actually funny and never juvenile, and the dramatic and sad moments are handled with great care without making too big (and heavy) of a scene when they happen. There's great balance in all of it.

The acting is also great. The best performances were from Gemini and Fourth, and I have to say that it was an amazing first impression: the feelings and inner thoughts of their characters are vivid in their gaze and their actions at all times, I was amazed from the very first episode and that is also what got me so engaged. The dynamics between characters are also immaculate: all the friends feel like actual friends and there's no hint of awkwardness among them - if anyone told me that Chinzhilla is an actual band in real life with the same members as this series, I wouldn't even question it. The dynamics between parents and sons are also excellent, probably the best I've seen in any series so far. No character is flat, all of them have some level of depth and more facets than it might seem at the beginning.
The relationship between Tinn and Gun develops in stages, and I was able to see the characters slowly transform across the episodes. It's something I don't get to see often enough in any story and I loved it.

I usually don't pay attention to the music, but this time around it's necessary since it's one of the main elements of this series. Each episode comes with a new beautiful song that helps exploring the many emotions and situations that the characters go through, and the variety and quality made them all very memorable. It's not a musical, but music is a key element both for the plot and the character introspection, and I loved how the OST was used so well to communicate that.

Definitely one of the best series I've watched - not just among BLs, overall. It's hearwarming, cute, VERY satisfying, and just so, SO precious.
I recommend staying away if you're looking for "hot" kiss scenes or anything like that. If you're looking for pure chemistry and a healing plot, this is a must watch!