I'm unsure if its because Koushin Koinu ni Koibumi wo or A Love Letter for the Marching Puppy is only 9 chapters in, but I believe this is one of the most underrated yuri mangas out right now! It's a senpai/kouhai story like Bloom Into You & the two share the sweetness between the couple, so I do recommend this manga especially for fans of Bloom Into You because of that. This manga isn't just a copy of Bloom Into You however as the mangaka [Tama Tamasaki]'s decision to make the setting/environment of a military school in A Love Letter allows different problems & situations
for Shinobu & Kagami. In fact, I think the environment of this manga is what makes this manga refreshing & unique especially refreshing compared to the other popular series in its genre (or at least from what I've read in the last two years).
Mangas such a Bloom Into You, Citrus, Girlfriends, etc. are always taken place in urban/suburban areas so it's no surprise that these series will have a good amount of setting situations in like (ex. going shopping at a mall) [side-note: I'm avoiding the shonen yuris in this argument]. Because A Love Letter is at a military school, the dates themselves are different themselves & are treated differently as there's only certain times where the main couple can actually go out [because the military]. Along with that, when I talk about the environment, it's not just the literal setting, but the characters within the setting. Now, again, the story is pretty new so I don't think this aspect is fully developed, but I think it'll develop as the story goes on; what I hope will happen is that we'll see a difference in a character's thinking process/decisions because of the environment compared to a regular schoolgirl's. I want to see the aura of the military in this setting affect these girls as the story progresses especially since a lot of the character archetypes are those that I've seen before in my two years reading [which is why I gave character an 8].
I think this series has potential to say the least! Never have I gotten so pumped to read more for a series in my two years! Never have I ever read a series religiously because I'm so impatient! I would recommend this series to everyone who shows any interest towards it! The one thing that would ruin this series is if the military school environment becomes irrelevant to the characters.