If there was an ass expansion version of Manyuu Hikenchou i’d hate to see booties shrink. However I have a solution. Something happens to Chifusa making her breast flow not work the way it’s supposed to, so every time she absorbs someones breasts it goes straight to her ass every time without fail. Either that or there is a secret clan that hates breasts and is willing to shrink everyones breasts for a bigger ass.