Singlet by wrinqle, the in-house brand of inoue pleats co. Made from a yellow and green pleated polyester fabric, it is dramatically small when laid flat but stretches substantially to accommodate the body. A red version of this singlet is available here.

Size M - L (JP womens), may fit smaller
Check measurements to confirm fit
All measurements taken flat
Garment has stretch

Shoulder width: 21 cm
Width (at underarms): 25 - 45 cm
Length (neck to hem): 50 cm
Hem width: 25 cm

100% polyester
Made in china

More wrinqle items here. Or read (a little) about inoue pleats co.