And this is the case, a puzzle of 6,000 pieces of japanese brand Tenyo, and so far we did not know of its existence.
The image of the puzzle (Mickey and Minnie Mouse) is not usual in puzzles for adults, and especially for a big puzzle, but I think it has its charm.
The puzzle appeared recently at an auction of a page of Japanese sales, and few data are known; It comes in 4 bags and seems to originate from the 1980s or early '90s.
Dimensions, 168x120 are really great for a puzzle of 6000 pieces, and more for a Japanese puzzle (only surpassed by the map of Central Hobby with 219x102)
The Japanese title is "ク リ ス タ ル な 想 い 出," which google translates as "Crystal of memories" in English or "Cristal de recuerdos" in Spanish.
The reference number is 6000 980 D.