In 2012, I bought one of those cheap extendable China-made luggage, that has a wooden base with 4 rollers. About 3000+yen Can really hold a lot of stuff but very hard to handle and damn noisy on the pavement. Had to throw away some of the model boxes, but I try to keep those of the more expensive models. Took SQ.
In 2013, I bought a 40L adidas sports bag, stuffed it full with boxes and risked it by checking it in. Turned out 2 boxes got dented a bit.
Bought a lot of artbooks too, stuffed them into my carry on bag and brought them on board. Definitely weighed more than 7kg which was the limit, lol. Took MAS.
In conclusion, I did 2 check-in luggages for both trips, one for my own stuff, one for my models. So no, 1 check in is not enough, haha.