Japanese astronaut Koichi Wakata is testing out some new threads provided by the Japan Women's University in Tokyo. Koji Yanagawa, a director at JAXA, told Discovery News that Koichi can "can wear his trunks (underwear) more than a week," as the special outfit is threaded with anti-bacterial and deodorizing materials. That's especially important as astronauts can't afford the luxury of a large wardrobe in space, and regularly washing clothes isn't a chief concern — but it's not like you can just ignore a bad smell on a space station, either.
The clothing has already scored high marks with the Japanese astronauts who have tested it, as not only is it comfortable, but it keeps them dry, insulated, and it's fire and static resistant. Even with plenty of exercise — extra important to astronauts — the clothing holds up. Japan plans to distribute the clothing to other nations participating in the construction of the International Space Station as soon as it's done testing.