JA8942 was one of the first 2 Boeing 777-300s (not an ER) retired from JAL's fleet - JA8941 was the other. They were the first 2 of the type delivered to JAL in 1998. Why only 17 years service? They were used almost exclusively on short-range Japanese domestic routes so had a lot of cycles.
Interesting how they disassembled it via the actual sections used when constructing it. I wonder why? If it is just being scrapped I would have thought that they would just run a saw through it like they usually do. Surely they wont sell fuselage sections as a replacement part?