Yes!
Sorry... I don't know how else to say it... Just "Yes".
Along some others... This is my favorite type of Sumo Transformation; with a "Magic Mawashi", [or "Sumo belt" if anyone didn't already know].

An enchanted mawashi puts itself on to someone, unable to take it off, and the mawashi starts magically making them gain weight.
And while that is happening, the belt starts changing they're mindset, so they believe that they were always this way; A Sumo Wrestler.

Great work! :D