As rluka has stated earlier, even though NTR is in the title, there isn't actually any NTR. The actual web novel is pretty good and I highly recommend reading it. I should know, I donated some dono's to the guy translating it
The way I would describe this series is a slice of life/cute romance with some eroge like elements. Heck, take the eroge elements out of it, I think it would still be a solid read. The eroge like elements only enhances it. There's standard drama of course, but nothing too crazy, and given how short the novel is (its less than a hundred chapters), wrapped up stuff nicely.