QUOTE(matt85 @ Mar 24 2011, 07:01 PM)
Feasible, if you:
1. Decide skip trains and walk from Ueno to Shibuya.
2. Eat only onigiri/sand.
3. Drink from temple/taps.
4. Sleep in capsules/join the homeless.

Don't know if he is just being sarcastic but just in case you need to know, there are many ways to cut back a lot if you are there for a long stay.
1. Yes, have good walking shoes. It's not that far between 2 or three train stops. Even in winter, walking keeps you very warm. Group all your distance travel in town on the same day and use an all day pass. Take the slower train or bus from the airport. Don't ever miss the last train at night or the necessary connections.
2. Those are not really cheap and you might get malnourished. Try to get lodging where you have some way to heat up food like a microwave or even kettle. Then you can get inexpensive stuff from the supermarket like eggs, sausages, make your own sandwiches to carry out for meals. Look for late afternoon, late evening clearance tagged fresh food items. The convenience stores usually have cooked eggs, dried meat/seafood snacks, fried chicken pieces. You can have these for the price of onigiri. Try the free samples in the food section of department stores early evening.
3. Fill a used plastic drink bottle and carry it with you. Fill with tea, coffee, milk or juice when you leave and then refill on the street from drinking fountains or even restroom taps. Buy soft drinks (and many other things) in the 100 yen shops.
4. Look in the free English tourist magazine listings for a guest house room to rent by the week. Some Japanese stay overnight in train station corridors but probably only if they are waiting for the first train. If you must do it, don't look too shabby to attract police checks. See if there is a manga shop nearby where you can sleep on a chair overnight for a small price. Luggage can go into station coin lockers.
Travelling in Japan, be proud to be a cheapskate; blowing a big load of Malaysian cash will not compare with what Japanese spend when they want to impress!
111