As to the ending, I think it was abrupt but fine. You can't expect a true ending in a slice of life, but in terms of typical slice of life, it's better than most.
As an aside, I like how in the last panels with Kou-chan, her hair is the original style. A detail that I found irksome was that...
I bought this series up to Vol 8, which actually came out the day I was leaving Japan back in 23. I do plan to grab the last volume here in a few months when I return.
I could scan Vol 8's extras but it will not be the best quality as I will not crease my books. They're actually still...