Cheongsam Cantonese for "long dress." A traditional Chinese dress, originally Manchurian qipao ("banner gown"). See Chinese Fashion (which also includes this History of Cheongsam), Qipao / Cheongsam, Wikipedia, or Everything2.
Gaku-ran Military style uniform worn by Japanese schoolboys. See Wikipedia.
Geta Japanese sandals, traditionally wooden, though modern ones may not be. They're raised on two strips. See The Geta Page, JapaneseKimono.com, Wikipedia, or Everything2.
Gi Clothes. Also short for keikogi.
Hakama are a type of outerwear, pleated pants or skirt, worn over a kimono. See JapaneseKimono.com, Wikipedia, or Everything2.
Happi An overcoat traditionally worn by shopkeepers, which is now often used as a short robe for festivals, etc. See JapaneseKimono.com or Wikipedia.
Keikogi Training clothes. Worn when practicing martial arts. Also called "gi" or "do gi." See Wikipedia or Everything2.
Kimono means literally "clothing" or "things to wear," though of course we have a specific image of kimono as a particular type of Japanese clothing. Kimono are today usually only worn on special occasions. See JapaneseKimono.com, Wikipedia, or Everything2.
Nemaki Sleepwear. See JapaneseKimono.com.
Obi A sash worn with a kimono. See JapaneseKimono.com, Wikipedia, or Everything2.
Qipao See Cheongsam.
Seifuku Uniform. See Everything2.
Sera fuku Sailor suit, which is worn by Japanese schoolgirls and is often seen in anime. See Wikipedia.
Shibori See arts page.
Shihakushou I'm not sure if this word actually is used anywhere except the anime "Bleach." In that, it refers to the uniform worn by most Soul Reapers, which consists of a white undershirt, black kimono and hakama, and a white sash (apparently not an obi, not that I know the difference).
Tabi Japanese socks with a split for the big toe, so that they may comfortably be worn with sandals. (Tabi can also mean "journey.") See JapaneseKimono.com, Wikipedia, or Everything2.
Tatami A type of zori sandals made of straw, like tatami mats (see stuff page).
Uwabaki Indoor slippers or shoes to wear after removing your outdoor shoes in the genkan (see stuff page). I'm not sure, I think maybe this word only applies to slippers worn at schools...
Yukata An informal summer kimono or bathrobe. See JapaneseKimono.com, Wikipedia, or Everything2.
Zori Any Japanese sandals with a flat bottom. See JapaneseKimono.com, Wikipedia, or Everything2.
Ganguro Black face. A trend in the '90s, where Japanese girls would imitate the look of California beach-bunnies by bleaching their hair and getting deep tans, as a rejection of the traditional Japanese feminine ideal. The trend was later revived as manba. See Wikipedia or Everything2.
Harajuku girls An eclectic style, or rather any number of different fashion trends might fall into this category.... See Wikipedia.
Lolita is a fashion trend which includes various styles, most notably Gothic Lolita (GothLoli, Loli-goth) and Sweet Lolita (amaloli). Basically, it's about trying to emulate Victorian fashions, and also look childishly cute or even like a Victorian doll. Of course, as the name Lolita suggests, there can sometimes be a sexual aspect to the childish nature of the fashion trend. See also rorikon (sexual terms page; discretion advised). See Avant Gauche, Wikipedia, or Everything2 (Gothic; Sweet).
Manba Short form of "yamanba," which means "mountain hag." It's a more extreme version of ganguro. See Wikipedia or Everything2.
See also: culture page, store links (under apparel) and tek's links: stores (under international merchandise)