Travel Laundry Bag Any Good Cheap Places In Japan To Do Your Laundry?

Any good cheap places in Japan to do your laundry? - travel laundry bag

I'm going to Japan soon with friends and we plan to pack light enough to travel, not to interfere with our bags of clothes that she thought it would be better off if we wash the clothes. Any suggestion or cheap places to know people?
I know it's a bit like a strange question, but Deffinatly help if someone knew a good thing.
Thanks
xx