There is no clothing on earth that would mould itself so tightly around Macha's weird little plum-tits.
A problem entirely too common with manga artists, unfortunately. They forget so easily that clothing has its own structure and tents accordingly, and highly elastic clothing also tends to exert a level of pressure on soft flesh. In order to shape itself like a second skin as shown in the case of Macha's outfit, her clothing would probably need the consistency of warm bubblegum, molten rubber or body-paint.