Lessons from Sumo
I've always enjoyed sumo wrestling for a few reasons. It doesn't have to do with the obesity, blood pressure problems, or decreased life expectancy of the average traditional wrestler, and it definitely doesn't have anything to do with the mawashi (those "diaper"-looking outfits).
It has to do with the simplicity of the sport itself. Two wrestlers in a ring, first one out loses. Simple enough, but definitely not easy. It gets even better when you get rare situations like the video above. Hurray for the underdog.
Of all the traditions associated with sumo, there's one that's pretty misunderstood. Their nutrition. Contrary to the idea that "sumo wrestlers eat anything and everything", there's one particular calorie-dense stew, called chanko, that serves as a cornerstone of their nutrition plan.
There was an TMUSCLE article written many moons ago, that explained how to adapt the chanko concept to a muscle-building, mass gaining plan.
For another take on it, here's one recipe for a traditional chanko stew. It explains the general idea, but you can definitely tweak it to your own preferences. I'm guessing that you don't need to avoid beef or fish for superstitious reasons, so go for it.
If you're looking to start adding some serious size, consider breaking out a crock pot and give chanko a chance.