For all the fellow Indian Traveller, It's my suggestion do carry Japanese Yen or Dollars or Bank cards for any kind of transactions. The most important thing is Japan does not allow Indian INR at any place not even the money exchange of the airports. From my experience I can tell you all is be cautious about this matter if you are an Indian or carrying any INR.
I roamed about the city of Tokyo , bank to bank and couldn't find any help. Lastly on the day 5 I met a random Indian at the Tokyo Sky Tree who helped me with this matter and I lived in Tokyo for the next 2 days of my trip.