Make a sumo wrestler costume using a flesh-colored Lycra bodysuit. Turn the suit inside out, and cut pieces of cotton padding to fit the suit. Use padding to fill out the suit's arms, legs and torso, and secure it using strong fabric glue. Leave the suit inside out while the glue dries. Use a length of black fabric to create the wrestler's loincloth. Complete the costume with a kimono and topknot wig.
To make the loincloth, bring the length of fabric between the legs, and then wrap it around the waist. Pick a point where the fabric overlaps, and attach a Velcro strip to make the loincloth easier to put on and secure.
To make the topknot, style a black wig into a small, tight knot, and secure it with pins. If you do not plan to reuse the wig, spray it with adhesive to ensure it stays secure. Complete the hair with a hair stick. For an added accessory, wear a kimono over the finished costume. For footwear, use black loafers or flip-flops.
If you do not have a bodysuit, try stuffing flesh-colored tights with newspaper. Newspaper is lighter than cotton or foam, and also does not trap as much heat.