"Arashi, the diligent polar bear butler, and Setsu, the slightly un-diligent bodyguard, both live and work under Mikan, the young lady of the Shirasumioka family. One day, she happens to witness these two polar opposites secretly kissing...? This is a manga about such a young lady and a human x beastman couple of retainers."
This is not actually the book, but the entire story that was posted on そーちゃん's X/Twitter. So there's no 6 additional pages, nor the end colophons.
I do plan to buy the sequel though, as soon as I have the finances to do so...
Note: the "sister" is intentional even though they're cousins. after reading it again I realized I haphazardly used 'Miss' and 'Lady', so please note that they are somewhat interchangable