Kids On the Slope is a solid piece of work, but it pales in comparison with other works of the same or similar genres. What's wrong with it in my opinion? It feels unnatural.
In other words, the progression of events and the interaction of characters make me feel like they are what they are for the sake of the storyline and overall atmosphere. It's like, you first create an unchangeable backdrop and lot of things to be done and then make some characters fit in some roles to do those things. I didn't feel any deeper traits that actually defined each character, so consequently, whether or not the characters are what they are doesnt really matter to the story anymore, since the story would nevertheless progress the way it was written. This type of progression might work fine for horror or mystery, but definitely not for drama or slice of life. I believe that the importance of each characters foremost must surpass the importance of the storyline in order for a drama to be successful. Otherwise, there is no point in watching it since it would be too trivial.
Another thing about this series is that the story lacks anything that pops. You can say that's the way Josie series are. However, for me this can only mean the Josie genre needs a breakthrough. Anyways, for me, no matter you use which genre to define this show, it doesn't live up to the potential in any of the genres.
However, it is a solid piece of work. From the music to the animation, there is nothing one can really complain about. The big picture is perfect, but too perfect for the characters to shine through. That's why I couldn't bring myself to like it as much as I wanted to.