How much Yen do I need for a weeklong trip?
 

I get told that several places use cash instead of Visa.
How much Yen do I need to take with me for a week long trip?

A lot depends on how much your budget is and what you are going to do during the week.

Eating out for instance, there are plenty of places where a decent bowl of Ramen can be had for under a 1000 yen or multiple Michelin starred restaurants that run into hundreds of dollars for the meal.

My suggestion would be to get about 20000 Yen at an ATM on arrival at the airport. Use the ATM not the cash exchange for better rates.

Then get yourself a Suica or Pasmo card at the airport and load it up with 5000 Yen initially. The Suica or Pasmo cards are used for tapping on and off of subways, trains and buses and can also be used to pay for goods in conbini’s and other places, including some restaurants.

Top your Suica or Pasmo card up as required and get Yen out of the ATM at 7-Eleven as required. 7-Eleven are everywhere and all have ATM.

If you have an iPhone, you can add SUICA to your iPhone wallet and top up in 1000 yen increments from your credit card. That will reduce your need for cash.
You can also reduce cash transactions by avoiding family-owned restaurants, but I don't recommend that at all.

Only thing I can add to this is that some restaurants will say they take cards, but they'll have a minimum amount of 4-5000jpy to be able to charge your bill, so it really does depend on what you plan to do and where to go. Entrance fees to cultural sites or museums can be cash only as well.
It's becoming more cashless, but as noted above, some of the smaller privately owned restaurants are cash only, even in touristy places like Asakusa.
I bring about 100k jpy in cash with me as an initial fund, but I tend to do cash only things like going to the arcade or the horse races during my time in Tokyo.

Good to have 500 yen in 100 yen coins for the odd locker needs in museums etc

This actually reminds me of the time I had trouble paying for my ride on the Hiroshima tram prior to Suica/Pasmo being accepted on it.
Didn't have coins beside 500y and didn't have a Paspy card.. I assumed the machines at the front had the change dispenser like the buses in Hokkaido but they didn't so I had to ask the attendant to break the 500y into 5x100y which almost made me miss my stop.

If not visiting a keibajo then 30,000 will do. Or even half that (~a hundred bucks walking around money)

What I've been doing is taking about JPY20,000 at a time out from a 7-11 or Lawson ATM (foreign bank friendly machines) and using it here and there as I go, and then all of the excess cash, save for maybe 1,000 is given to the hotel at check-out as partial payment against the final bill, with the balance going to my credit card. That way I never need to worry about orphan currency.

It's better to take out more than you really think you need and deal with the excess this way rather than continually visiting the ATM and racking up bank fees.

Will this Suica Android app do the trick:
https://play.google.com/store/apps/d...expensetracker

Can I use it 7-11 ATMs to take cash - android app on a Moto?

I will be there for 2 weeks actually.
45k yen is sufficient?

You're talking about cash, right? Not the total budget for two weeks.

1. Do you intend to use a credit card for most transactions?
You can use cards for most things. Over two weeks, if you take care to avoid shops that don't take cards, you might even get by without using cash. That said, you should probably have at least 10,000 JPY on you in case you find yourself in one of the very few remaining taxis that doesn't take cards, or you have dinner somewhere and realize at the last moment that the restaurant doesn't accept credit cards.

2. Do you have at least one ATM card with a pin number that you can use to withdraw cash from an ATM? Check that you can use it at 7 Bank ATMs.
https://www.sevenbank.co.jp/intlcard/card2.html

I suggest that you withdraw 10,000 to 30,000 JPY from an ATM when you arrive in Japan and only make further withdrawals when your cash reserve gets low. You should quickly get a sense for how much cash you'll need for the whole trip.

That app is only for checking balances. Need an iPhone or Japan native Android phone for mobile IC card usage in Japan. And IC cards or phones do not act as debit cards at ATMs.

Sure, that will work.

If you have a brokerage account or 401K then see if they offer a checking account with debit card that refunds the ATM bank fees. The bank fees for the Japan bank are minimal but your home bank fee might be a bit of a spanking (USA banks, anyway)

At the ATM you may be given an option to do the transaction in yen or in your home country currency. Always choose yen. The other option is a ripoff called dynamic currency conversion.

@bocastephen mentioned using orphan cash to pay down your final hotel bill. That is an excellent idea.

Sometimes my final stay is on hotel points. In that case I just hold on to the cash for a future foreign trip. JPY are easy to convert all over the world. I carry the cash (paper money) to convert in case I have any issue with using an ATM.

One time, I won big at Woodbine and was unable to convert the CAD to USD before my flight home. Used it to buy yen in Kyoto.

Assuming you use credit card for most things and aren’t going into really outskirt areas, yes. My last two 2 week trips for 2 adults and a kid I brought about 55k yen in cash and by the last few days was forcing myself to pay for things in cash.

After a day or so you will know. ATM's are everywhere. Don't stress.