Now. ...is this a song joking about phallic comparisons? (I.e. Hey! You're big -- IN JAPAN! )
Or a song about relative obscurity. Hey at least we're something - you should come along. WE'RE BIG (a huge hit) in JAPAN!
or is it simply about physical stature? (*i.e. nearly everybody is big in Japan)
"Come tonight! Come see the Overbite! Come to Ogre Battle, FIGHTt!"