Probably the best word to summarize the entire series would be soft. The animation is very soft and gentle, easy on the eyes. The music is mellow and lets the viewer focus more on what they're seeing, acting as support rather than boosting emotions. The overall tone and plot are very soft too, as we're watching romance unfold. It's sweet, but could it be too sweet?
Fun fact about the title of the series is that Tsukigakireri can mean as the moon, so beautiful, as well as I love you. It's a bit of a play on words, which I thought was cool. But anyway, back to the topic at hand. I really want to say that I love this series, it does have a lot of interesting aspects to it.
It's so cute how the main characters start to open up to each other, like how Akane Mizuno calls him Curly-Kun because of his bedhead. We see them progress from humans with social or emotional issues to these cute little kids expanding their horizons. They're not only opening up more to each other, but to those around them as well. Keep in mind that they're all in their third year of middle school, which means they're all about 15 years old, the equivalent to a high school freshman in America. They're just hitting that age where they're finding themselves and all that. So it's classic coming into age journey material.
Another cool thing, in the beginning, was how the male main character Kotaro Azumi made a reference to Dazai Osamu, who I'm a personal fan of. He seems to really respect and admire Dazai, which is so cool. The creator of the series really appreciates his work, and it can be shown through quotes and excerpts that aren't very commonplace. But that's more of an easter egg.
The romance is great, but in all honesty, it's very slow paced. It also gives the viewer the frustration of wanting them to just get over it and let their love run free or something like that. It's too mellow, it gets boring and it feels like you're forcing yourself to watch just so you can get to some sort of action. The music is good but it's so soothing it just makes me want to fall asleep.
If you're into cute high school romance and nothing but fluff, then this is for you. But for anyone else, it's just way too boring and vanilla. It doesn't have any sort of marketing value for anyone besides people into the sweet enough to make you sick genre, and even then it's a little difficult. It's one of those dime a dozen types, so really it's either you like that and should check it out, or look into other series because this one is pretty much a bust.