Masktchis are easy to get. ^^
Don't fill the hungry and happy meters over TWO hearts, keep their training two points or under, and let their meters empty a few times. After they turn inot a teenager you can fill up their meters fully, but don't play with them. It ruins the work. xD
They will way over 90 pounds when their adults, but just play the jump game up to four hurdles and stop, they lose three pounds at that point.
When they get married and have kids, the child will most likely be a Masktchi or Gozarutchi. I had 5 generations, until I got a Memetchi. (After two generations you can fill their training one point below, and meters, full their whole life and they'll still be the same type)