>  We are a family traveling from San Francisco, California with an elderly mother who now needs a wheelchair. 
>  Can you help us with information about wheelchair rentals or loans? 

No rental and loans for travelers.
Buy it. About 200 US$ so far. But you must find the shop.

Well, many rental wheelchair each place, shopping mall, museum, big station, airport, park. hotel.. 
All free of charge to use, but you cannot take it home and hotel. 
You are allowed to use it inside the facility only. They are afraid when the wheelchair is broken outside. 
Renting a wheelchair each spot is one of solution.

>  I would like to enquire about disability train fares in Japan 
>  as my older brother is in a wheelchair and will be visiting Japan soon. 
>  Is there any discounts available for trains to the disabled and if there are what are the prices ? 

No any discount price officially if you do not have Japanese disability ID. 
Trains, normally half price, both disabled and attendant.

>  Could you please tell me how to get the disability discount card for visitors in Japan ?

That is only for person who has Japanese nationality.
But you may sometime get disability discount if you use wheelchair or cane, etc .
Show them your ID and say "this is my disability ID".
No Japanese knows your country ID and language as like you do not know Japanese disability ID..

>  Are accessible restrooms easy to find ? 

Easy. First, many public restrooms in Japan. May be the most in the world.
Today at least one accessible toilet in public restrooms.


>  Are accessible restrooms in restaurants ? 

Not all. But some big restaurants have large restrooms. 
Shopping mall and restaurant floor of big buildings have accessible restrooms.
It is rare to find accessible restrooms in a small shops and restaurants, cafe, bar in Japan. 

>  I saw a lot of hotels with wheelchair accessible rooms and bathrooms on your homepage now. 
>  But my question is: how does wheelchair-people can use a bath tube without a seat where they can sit ?
>  We have such sitting-board at home, that we just put on the bathtub so my friend can sit on it
>  Can we lend such sitting-board in the hotel ? or do we have to bring it from Austria?

First, Japanese bathroom is different from Europe one. Also accessible bathroom is different. 
Bathtub is also different. More deep. We Japanese like to sink our body deeply inside. 
Shower chair is standard in Europe. 

We have a space washing our body and hair in bathroom.
We never wash our body and hair in bathtub at house, but some economy hotels have no space of washing.

Bathtub is standard facility except economy hotels. Our bath tab is large and bid sitting space available.
Sometime shower chair available, but no sitting-board in bathtub in Japanese accessible rooms.
We recommend that you bring your own sitting board or shower chair if it is small.

>  I will be in Japan for 7 days in December: Tokyo and Kyoto.
>  I cannot get in and out of a bathtub and I am having a problem locating hotels 
>  in the 2 cities without a bathtub and with a roll-in shower instead. Can you help? 

Normally bathroom of Japanese economy hotel is very small and with a step.
There are no shower wheelchair, but some have a shower chair.
Public welfare facilities have a special room with shower wheelchair, but located far from city center. 
Bringing your own shower chair is the best way and safety. 

"Toyoko Inn" accessible room has a large bathroom.
They put a shower chair in shower area and also have another bathtub.
This is one of the choice. Price is cheep.   http://www.toyoko-inn.com/eng/

Tokyo. Keio plaza is very famous for accessible room.
They put on shower chair or bathtub board easily.
Just book the cheep price and request to change wheelchair accessible room.
Free upgrade. Secret way.   http://www.keioplaza.com

Kyoto. Bathroom space is up to the price of hotel. Toyoko Inn is large and cheep.
Some luxurious hotel have accessible rooms but normally no shower chair.
You can enter the bathroom by own wheelchair.
Check our list.   http://www.japan-accessible.com/sleeping/kyoto.htm

>  I'm a wheelchair user, very strong and independent, with an ultra lightweight manual wheelchair.
>  It's proving difficult to find an accessible hotel room where I want to stay, 
>  namely downtown, handy to the Yamanote line.
>  So far I'm only able to find a room that will cost me $200 per night.

Check this page.  http://www.japan-accessible.com/sleeping/tokyo.htm
Recently at least one accessible room each hotel, but booking it by phone.
For foreigners, it is not kind system. We can call it instead of foreign wheelchair tourist.
Some hotels you can book accessible rooms by web or fax directly. 200 US$ is enough to find.

> I would like to find an onsen accessible. I have a prosthesis instead of my leg, 
> so, I don't know if I can go in all onsen or if there are accessible onsen.

Many Japanese elderly people love onsen. Big shower chair and hand rail to bathtub there.
You cannot bring your prosthesis inside onsen because of sanitary reason.
Also it is not allowed to put swim wear or clothes to enter onsen in Japan.

The floor is very sleepy. One leg jumping walk seems dangerous.
You need your own cane. Just clean the cane and bring it inside onsen, but do not use in the bathtub.
Some private onsen room is small. Nobody there. You may move by hand on the floor.

> I need a patient lift in daily life for transferring from bed to wheelchair for example.
> Could you tell me where I could find a patient lift ? 

Patient lift is not popular in Japan.
Some facility and houses have electric lifts. We do not know why we do not have a patient lift in Japan.
Sorry no rental equipment in Japan. You must bring your own patient lift..

Free to download " Pointing Conversation for Accessible Tour in Japanese ".