Looking for room or apartment rental in Tokyo

Two acquaintances of mine will visit Tokyo in September. They are looking for a furnished apartment or room where they can stay for around 3 weeks. Could someone tell me which are the best areas (in terms of safety, convenience) where to stay? They would like a quiet place near the subway station so that they can move around by subway.
If you also know the estimated costs I will very much appreciate it.
Cintia
Buenos Aires, Argentina

JR should make Espaﾃｱol pages!

I think areas aren't the prior factor for foreigners who want to rent a weekly/monthly apartment. Basically, Tokyo has no danger area and money makes it very convinient in every areas.

So, please tell us
1)what is the purpose of visiting Japan.
2)how much is their budget for their apartment.
3)whether they will buy the Japan Rail Pass or not.
4)whether they want a (small but)natural spots like park,garden,river as there "quiet place" or not.

And here's a portal site about weekly/monthly apartment(but written in Japanese).
東京都のウィークリーマンション,マンスリーマンション探しの達人

sakura house or leo palace, i've heard
good luck

Dear Kara and Budd, Thanks for your responses. The people who want to visit Tokyo are in their fifties, they are both professional (married couple) and they will go on vacations. They have no idea about costs for apartment rentals as prices are totally different from Argentina, so they are looking for something not very luxurious but quiet and good. View is not essential but would be a plus.
They will probably by the Japan Railpass. Thanks for all your help!

Too hard to choose from

Their requests are too ambiguous for me, so you'd better decide it for themselves from these English links below.


Guesthouses&Furnished apartments:
Borderless-Tokyo 国際交流協会ボーダレス東京 | 東京シェアハウス・ゲストハウス
gaijinhouse.net http://www.gaijinhouse.net/indexe.htm
GUESTHOUSE =THE WIND SITE= mjukis.net
JAF-Plaza http://www.jafnet.co.jp/plaza/contentse/e_top.htm
KHAOSAN TOKYO Cheapest Hostels Across Japan : Khaosan Hostel Group
OAKHOUSE http://www.oakhouse.jp/english/index.htm
Sakura House http://www.sakura-house.com/index.htm
Satsuki House http://koyomiya.jp/english_s.html
TATAMI-GUESTHOUSE http://www.tatami-guesthouse.com/

Monthly(Weekly) Flat/Houses:
Kurumi mansion http://www.tmb.co.jp/~kurumi/eigo.html
Leopalace http://www.eg.leopalace21.com/
MONTHLY CHINTAI http://www.monthlychintai.com/english/
PAL http://fudosan.yoursnet.com/
Serviced Apartment with Urban Comfort http://www.bureau.co.jp/en/index_nonfla.html
Tokyo Rental http://vizionsgroup.com/tren/
Winbell http://www.dango.ne.jp/winbell/english.html

Monthly(Weekly) Flat/Houses for 2foreigners(written in Japanese):
Weekly Monthly Tokyo(52 hits) http://www.wmtokyo.com/top6.htm
Create Monthly(59 hits) http://www.monthly-create.com/search/
Monthly-Shintoshin(22 hits) http://www.monthly-shintoshin.com/search/search.php3

Useful info for travelers in Tokyo(Japan):
JapanReference(this site):
https://jref.com/dir/Travel_&_Tourism/index.shtml
Travel to TOKYO
http://www.digi-promotion.com/
YES! TOKYO
http://www.tcvb.or.jp/
YOKOSO!
http://www.japanwelcomesyou.com/

for Argentinian:
http://www.geocities.co.jp/Milkyway/6461/POLOS.html
http://www.tanimon.com.ar/introduccion_es.htm
http://www.geocities.co.jp/HeartLand-Himawari/3403/

"Their requests are too ambiguous for me,"
yep
those are some phat links. thanks!

Dear Kara,
Thank you for such useful information. I really appreciate your help.