tl;dr: A simple story told in very subtle ways, with excellent acting and interesting camera work.

The first episodes make this series seem like a more depressing version of "BL Drama no Shuen ni Narimashita" but it is not -- the dynamics and the background stories are very much different.

It's a slow-burn romance and does have the often used tropes of non-communication, self-deprecation and mutual pining -- so if you're not a fan of these tropes, you might want to give this one a miss.

The narrative choice to tell only Shirasaki's point of view first and to show Hayami's story then only later, in episodes 7 and 8, is something we've seen in other J-BLs (Mr. Unlucky, Senpai This Can't Be Love or the newer Living with him come to mind). Usually, it works fine. In this case though, I think it was not a good choice.
When we meet Shirasaki first, he is at his lowest, full of self-deprecation -- he is not at all a reliable narrator. Hayami, on the other hand, is quite unreadable -- not because the actor is bad at his job but because this is part of the character (Hayami's friend tells him exactly that in episode 7). So, for the first six episodes, we only get one (skewed) side of the story.
Because of real life issues, I had to take a break in episode 8 -- and after that I restarted the whole series. With the knowledge of Hayami's backstory, I was able to see things differently -- and what seemed depressing and a bit flat the first time, was actually just very subtle acting by both main actors.

Regarding the acting, the main actors are, in my opinion, excellent. Minuscule movements and facial expressions show the inner life if a viewer cares to look closely. Quite a few scenes have been taken in one single shot -- which shows the how good the actors really are.

Speaking of shooting the drama: I was intrigued by some camera angles -- we look through windows and through cameras, sometimes we are in vey tight spaces, feelinga bit claustrophobic -- and then some sces are wide-angle shots, and everything is only seen from a distance. Use of hand-held cameras in some scenes show the instability of the actor's emotions. Even just finding out how these choices relate to the character's emotions would make a rewatch interesting.

While I don't like the opening song, I do love the background music -- the piece itself was lovely, melancholic but strangely uplifting at the same time. Silence also played a big part in enhancing the scenes.

Overall, I think this series is not one to watch and forget immediately, rather it is to be savoured, and deserves a close look at its details.