Goyac does the purest form of fetish love confessions. Reminds me of that Strawberry Panic doujinshi that scared the shit out of everyone when Shizuma told Nagisa the same thing about her smell. About her everything. Because she's that special to her.
We have the same thing here with childhood frtends. Ever since they were kids Himawari just couldn't get enough of Sakurako's smell. And Sakurako's sadistic prank literally backfired here heh.
tl;dr: Himawari is gay for Sakurako *and* a foot and smell fetishist (on top of a masochist and a boobie monster lol).
I hate those cliffhangers between Himegoto Flowers but that was both amusingly lewd and extremely cute. It could have used deeper foot play, go go Goyac!