Japan is a good place to find cheap and good quality second hand stuff. Clothes, kitchen supplies, electrical appliances, bags... you name it and you can probably find it at some of the locations below.
1) Flea Market @ Tachiaigawa
A group of us went to check out the flea market in Tachiaigawa (立会川) today. I think it's definitely one of the best ones in Tokyo. Many stores and reasonable prices. Never pass up the chance to haggle for a lower price.
If you look around you can find some pretty good finds here. My roommate, Lisa, got a guitar with strings for 900yen and Andrew got a Yamaha one (w/o strings) for 1500yen.
You'll be able to find lots of clothes here to help survive the impending freezing cold in January and February. Winter jackets and lot of other clothes go for about 1000yen.
Check out the website for a map of the flea market- http://trx.jp/en/guide_2.php?pid=1&std=1
2) Book Off
All locations sell books, CDs and DVDs. But there are several locations that sell second hands clothes, electrical appliances, bags, sport equipments, camera, instruments... etc...
*** There are special days of discounts on the 10th, 20th and 30th of every month. On the 10th- 10% off, 20th- 20% off, 30th- 30% off.
We went to the one at Odakyunagayama (多摩永山) and had a really wonderful day of shopping. We bought things for our hiking trip to Nikko as well as some winter wear.
http://www.bookoff.co.jp/shop/shop71002.html
Check out the Book Off website for more information- http://www.bookoff.co.jp/buy/superbazaar.php?visual=bnr_tvcm
3) Bazaar @ Hiyoshi International House (HIH)
If you live in the dorms near Hiyoshi (Plume IS, Shimoda, HIH) I highly recommend checking the bazaar out for cheap and useful stuff.
By far the cheapest place for really nice stuff. It's usually held in one of the Lounges in HIH. There is not a lot to choose from because it is not very big but there's lot of random things you can get here for cheap.
I bought an electrical blanket (new) for 800 yen, 2 coats for 300yen and 500 yen, and 2 cups for 10 yen each. The 100 yen stores are great but you'll save more money if you can get most the things for your apartment here.
They hold the bazaar once after move-in (September/October) and also once in winter (November). I am not sure if they will have it again in Spring/Summer but the HIH bazaars are definitely worth checking out especially if you live around Hiyoshi.
4) Second hand clothes store in Jiuyuugaoka (自由が丘)
10 minutes walk from the station. Ask around for GAP and it's on the street adjacent to GAP where there is a row of trees and benches in the middle of the path. (If you can't find it, just walk around Jiuyuugaoka- it's a wonderful place to explore)
Will update if I find more cool places that sell second hand stuff.
