Thanks to everyone for replying so quickly and well informed.
The first day I got here (Japan) I simply asked the tourist center if they could recommend any hotels that cash payment was an option. She laughed and said that it was no problem and recommended the Ueno area.
And what do you know, the first hotel I stumble into "Suntargas" has a cheap rate, AC (thank goodness) , free Internet, razors, coffee, soap + breakfast
and gladly accepts cash.
A small modest room, semi western style, obviously not made for people who likes to sit in all day (perfect for me).
So everything is great for me and to this date I have already been to the park, two museums, the Imperial Palace, "Sunshine City" and pretty much all around Akihabara and got this cheap ass "DELL" at an outlet.
Best wishes
Mackan