Searching around yielded little to no results to answer your questions. However, after you provided the images of the posting, I was able to translate this image using Google's Image translator app on my phone. Although it's not perfect, every time is seemed to concluded that the bottom bullet basically said "No software on Side B, new software can be written."
Due to what little is available about this, I would believe that this game is only one sided.
Side note: I got some interesting translations, like the red text in the above image saying "Fur Peeler" - I think the red text says "Family Computer Disk System" but the plastic on the game case blurs it somewhat in the image