You don't need electronic help to take the subway in Tokyo. Most stations have a system map in English somewhere, as well as information in English about what is located at each exit. Even if you can't find these aids to navigation, there are (gasp!) paper subway maps that are easy to obtain and carry around.

Earlier this summer, I was in Osaka, a city I don't know well, and I had to visit a long-time client who had moved from one part of the city to another. My hotel was able to provide a paper subway map in English, and the front desk clerk traced out the easiest route on it. (It still required two transfers :() Once I arrived at the station closest to my client's office, there was an exit sign with the name of the office building in English.

Even if you get lost in the Tokyo subway system, it is highly unlikely that anything bad will happen to you, and Japanese people are usually helpful to puzzled tourists. Furthermore, since it's Tokyo, with tens of thousands of foreign residents, you may well find a friendly expat who will help you out.

Do try to lookup the exit number for destinations near large stations before getting on the train/subway. Exits can be on entirely opposite sides of a large station or different sides of a platform so it is helpful to know which group of exits to head for when you step off the train. Most first time tourists to Tokyo will probably go to Shinjuku, Tokyo, or Ikebukero station at some point in their trip and these stations have a large number of exits. There are large maps inside the station showing exit number for common public landmarks or even several maps of exit groups. Shibuya also has high ridership but less of a warren. It can be a bit overwhelming when exiting a train at rush hour so I've found it helpful to check ahead of time, especially for your first night's hotel.

Also, don't feel bad if you get lost on the subway or take the wrong train. It is totally normal (I still do and have plenty of visits to Japan under my belt).

HOTEL ROOM SIZES
Sometimes your hotel room size might come as a surprise. If you are planning to use hotels with ratings with fewer stars rooms can be very small. Most booking sites and hotel websites indicate the size of any particular room on offer, usually in square meters. 30SqM plus is very generous and 20SqM or less is small and 15SqM or less is minute (in my opinion). Smaller rooms tend to have no storage either so if you are travelling with a couple of normal sized suitcases the only place to keep them and access them is on the floor.
If space, tidiness and storage including hanging space is important make a note of the room size, whether it has one large or two beds, (two beds use up more space) and consider how much luggage you are travelling with. I have stayed in a cupboard sized room at NRT for one night before an early am flight but my luggage was waiting for me in the Black Cat depot at the airport so the room was adequate though there was nowhere to sit except to lie on the bed.

While I am quite willing to live with less space, this is a really great point to make to first time visitors. If you're mentally prepared for it, the tight space can be worked around, but if not, it could be a huge frustration. Hotel rooms do tend to be on the smaller side in general here.

I recently planned a trip where my traveling partner has less of a tolerance for cramped corners than I do, and it was a lot of work to find rooms in the 30 sqm range without being super expensive. Unfortunately, I don't know of any booking site that makes it possible to sort or filter by room size.

If you search on airbnb (for whatever properties are left) you can specify twice as many people as you plan to keep in the place, which makes a decent filter.

[MENTION=110495]angra[/MENTION] - I've noticed that travel.rakuten.jp currently lists the room sizes in search results if it is available but doesn't have a filter. I think Ikyu might also list the room size? Still, price filter and perhaps a Chrome plugin for regex search filtering for something like "3[0-9]平" would help if there's a next time. Neither helps first time visitors unless they use google translate or can read Japanese.

I'll also point out that soft suitcases which open from the top lid take up less floor/stand space than the clam shell type when open. Hard shell spinners are very common in Japan but you really need a good bit of bed or floor space to open them and there aren't many/any drawers in JP business hotels esp 13-19 SqM size so you'll be accessing your own storage/suitcase quite often. Such rooms usually provide 3-6 hangers and a hanging rod. Some chains don't use solid bed platforms so you can fit a suitcase under the bed if it isn't too high (also a good place to check for "final check for forgotten items" before checking out).

A good resource for those considering rail travel in Japan: jprail.com

I recommend looking at their ordinary vs. green class comparison if trying to decide between the two.

Street Addresses
 

What I have found most difficult in Japan is navigating street addresses. I was told that the #-#-# numbering systems refers to the block with no indications of where on the four sides of the block your specific location is ! I would appreciate any further insights from the Board. And thank you for this excellent resource.

Kit Kat
 

And another thing that I scratch my head over in Japan is the status of Kit Kat candy-bars in Japan. This seems to be viewed as a gourmet luxury item with fancy stores and exotic flavors such as Wasabi that I haven't seen anywhere else ! Does anyone know the story behind its elated status ...

I had the same thought when I saw your question.

Found the following.

https://www.telegraph.co.uk/food-and...enon-in-japan/

The addressing system is a little easier to understand if you start with good paper maps like Tokyo City Altas than Google Maps as Google doesn't show block numbering.
https://www.tofugu.com/japan/japanese-address-system/

Google Maps with street view & satellite view works pretty well for walking navigation if you have the time to research it in advance. Subway and train stations usually have maps by the exits showing the major sights and buildings so you know which way to turn. If you're looking for something in a city, don't forget to look up and down as restaurants and shops aren't always on the ground floor.

Realistically, Google Maps takes care of pedestrian navigation in Japan pretty decently these days. I only use a full Japanese address when addressing things like luggage delivery and even then, I get the hotel clerk to write it in Japanese because my handwriting is somewhat illegible in Japanese & only a bit better in English with cramped forms. Car navigation is by phone number or map code when using the "navi"/car gps. I use Navitime's JP website if I need bus stops as they're much clearer on exact bus stop locations and integrate more local bus schedules + fares. Most first time visitors probably won't need bus navigation through the countryside, though, and if they did, I'm sure the local tourism bureau or ryokan would try to help via e-mail in advance.

Also, speaking of Kit-Kats, there are duty free shops at Narita that sell that and other Japanese confections. I know I've encountered one airside in T1.