Hmm..this one's just a 'little' offensive.
See, here's the thing. I get you like to use Sumo Wrestlers as a fat joke plot device. But, culturally they are viewed with much higher respect. Seriously, I met one, you DO NOT want to mess with one. They are like...indomitable.
I would avoid using too many plot devices that poke fun at a particular culture.
But you are free to publish anything you want.
Just understand there 'are' consequences to well....everything. It doesn't matter what your intentions were or not, publishing anything will always gauge a reaction.
But I just hope you're not 'intentionally' poking fun at sumo-werestleres.
If you want my opinion, I think you should focus getting 'eaten by rats', a demise best reserved towards a general fat person as a message 'against' being overweight through gluttony. Like...that's the karma of purposefully ignoring one's health and indulging in being overweight.
I know my 'father' would take offense to this as it appears to him that you are attacking Japanese. Although, he gets offended very easily.
You get what I'm saying right?
Leave humorous racial discrimination out of your comics. No matter how minuscule it seems. It's just a suggestion.