So what's a FUNDOSHI ?!

Fundoshi (褌, Fundoshi^?) is the traditional Japanese underwear for adult males, made from a length of cotton. Before World War II the fundoshi was the main form of underwear for Japanese adult males; however it went out of use quickly after the war with the advent of new underwear, such as briefs and trunks, on the Japanese market.

Nowadays, the fundoshi is mainly used not as underwear but as festival clothing (matsuri) or, sometimes, as swimwear.

There are several types of Fundoshi, including Rokushaku, Kuroneko, Mokko and Echyuu.

The Rokushaku Fundoshi is a length of cloth, the dimensions being one shaku (34 cm / 14 inches) width and six shaku (2.3 m / 92 to 96 inches) length, hence roku-shaku. The fundoshi is often twisted to create a thong effect at the back.

Echyuu fundoshi is also a length of cloth, however it has a strip of material at the waist to form a fastening or string. The dimensions are 14 inches width and about 40 inches length, and it is tied with the material strip in front of the body. Echyuu fundoshi was the form of fundoshi most popular among Japanese adult males as underwear from early 1900s to the end of the World War II.

http://en.wikipedia.org/wiki/Fundoshi