Is there places to stay w/o booking?

Im planning on arriving in Japan with no reservation or booking of a place to stay. I would prefer a more cheaper place as me and a friend are backpacking. any recommendations...Cheap as in ryokans down to capsules. I need to know how accesible are these accomidations. Are there a lot of cancellations of rooms? can i find maps of youth hostels at the Narita airport? any info would be great

A real ryokan is the most expensive way to stay overnight in Japan, Capsule is one of the cheapest ways. There are hostel like accommodations who offer rooms without furniture and calling these rooms ryokan. You cannot stay overnight in a ryokan without prior booking, capsule in general is without booking. There is a tourist information at Narita airport who can help you with accommodation booking. There are youth hotels in Tokyo, in general pre-booking, curfew and 3 night maximum stay.
See under this japan-guide to get an idea about price range and even the possibility to pre-book.

Particularly if you have limited budget, it is better to plan and book ahead. You don't want to spend half the time looking for accommodation for the night. Also vacancy would depend on whether you are coming on peak travel season or not, so, as suggested, please read through this site and pick up good information :)

I very seldom book hotels in advance, whether it is Japan, Paris, London etc. and yes I am careful about not spending too much money. I have been doing this for the last 25 years.. last time we were in Japan was last October. Of course my partner and I are flexible; if we can't find a hotel in town A (we carry a big list of possible hotels) but find one in town D, even if it is 300-400 km away, this is where we go. instead of going to town A, B, C we went to town D (close to B)then C and finally A so it all worked out fine in the end.
the fact is big towns have lots of hotels and many are overlooked by foreign tourists as these hotels have no Internet sites etc. Airports and often major rail stations also have reservation offices that can find a room at the last minute..

All of the above is very true. And the poster seems accepting of the uncertainties of such a method. But many people are not comfortable about arriving without accomodations arranged. One factor to consider is that without knowing what area you'll stay in, it takes more time to determine a route for sightseeing. Depending on how much time you have, this can detract from a good use of your time. Red Frog seems an exception as he/she seems the consummate traveler.

You flatter me but I am sure others think that I am a fool.. part of the reason I travel without advance booking is that I fly standby. At any rate my parents and most other people used to travel without advance booking in the days before internet, e-mail etc. so this is normal for me.
I MUST ADD THAT I TRAVEL WHEN MOST PEOPLE AREN'T. Most people in my company have lots of vacations that we split in several chunks of at least one week and I choose slow periods for travelling. As far as loosing time re planning the sightseeing, are you kidding?? all year long I keep a running list of places I would like to go and see in various countries, also names and phone # of hotels, trains schedules etc. and carry that info in a small flash drive. If by chance I am in a town I may not have planned to visit at all it doesn't take long to check with the tourist office or even the staff at the hotel. Blame that on age and experience but I don't agonize about seeing as many "Must see" places as possible. When you are in a different town from the one you live in and more so in a foreign country, everything is interesting! Yes there are a few things that shouldn't be missed but many "famous sights" don't please everyone (no amount of money would make me go to Disneyland and Tsukiji fish market for example). There is too much hype in some cases and, also, one can't force people to like everything.

No, I'm not kidding (and thanks for the dig after I afforded you some respect). When you have limited time and funds, it's important to prioritize - for exactly the reasons you expounded!

not sure if there is any youth hostel around in Narita but reasonable places to stay near the airport and requires reservation. If you have a cellphone access, holding a reservation shouldn't be a problem incase you can't check in on time you can always call.

http://www.asiarooms.com/japan/tokyo/narita_sky_court.html

http://www.asiarooms.com/japan/tokyo/narita-area.html

*Youth hostels, etc.. around Tokyo;

http://www.jyh.or.jp/english/kanto/yoyogi/index.html

http://www.jyh.or.jp/