I liked this book quite a bit, even if some aspects of it weren't to my preferences.
The MC starts the book off having a girlfriend of 10 years, when the world is jolted by some strange phenomenon that changes everyone to be able to gain skills/classes as the world sees strange creatures emerge. Not knowing what is happening with the power and devices all out, the couple elect to find the girlfriend's best friend that lives about 8 miles away. Along the way, they have to find and kill a few beetles, and arrive just in time to rescue the friend from a lizardman creature. And thus, their adventures begin.
I am not a big fan of the MC starting with a lover for a harem book, because it deprives the reader of getting to enjoy that romance aspect. And the long term friend becomes the 2nd member of the harem. Since they've known her for years, this was fairly anticlimactic and involves no real effort on the MC's part. That was the only real negative I had with the book.
The intimate scenes were very well written, with plenty of spice to entertain. The plot featured a few staple tropes of the "world changes to have RPG elements", but it was done with enough flair to make it compelling instead of boring.
There's a third woman queued up for reasons she won't explain yet, and a fourth that will most likely eventually succumb to the MC's competence and charm. And I look forward to how that fourth will play out the most, because she has no set reason to get involved at this point.