Uzaki and Takagi Giantess Afternoon (FULL COMIC) (Gumroad)

When a quirky drink vendor shows up, Sakurai and Nishikata shrinks in front of their "big" friend Uzaki-chan and Takagi-san. They will remain shrunk for several days, in which both girls, now turned into giantesses in the eyes of the little ones, will take the oportunity to "play" with them, with the ultimate goal that they submit to them.