I actually can't find the seat maker for JL or NH, but this sounds exactly like the seat on NH's 787-9 also, pics I can find look the same as well. That's one of the most LCC like cut-rate business class seats I've experienced in modern times. They're fine if you want to sit up or lay fully down but are a complete disappointment for positions in between. I can overlook the airlines who still have recliners on regional aircraft (JL included), but to install these low end lie flats on a brand new plane isn't a good look.

Interesting what you said about having both a shoulder airbag and lap airbag, that would indeed be uncomfortable. But that's Japan in general for you, there are additional safety measures on many things that would be considered unnecessary and even absurd in much of the rest of the world. It's something expats living here learn to tolerate, but can be annoying. I did fly on a JL 789 last month but was quite hungover and just slept nearly immediately. I can't recall the seat other than the fact it allowed me to sleep the entire way from BKK-HND, but looking at the seatmap, it should have been the same one you're talking about.