I was looking for the same thing for a trip to Osaka last year. Found these two services will pick up, wash, fold and deliver. My Japanese isn't that great, but I think the one in the first link offers an in-store option. Maybe somebody else can confirm. Both charge by the bag. Didn't use them in the end as I ended up booking an Airbnb apartment that came with a washer and dryer.

http://www.laundrybasket.jp
http://www.demaeyahonpo.com/services.htm

In Japan, laundromats are called coin laundries. Not sure what they call Wash n Folds, but I searched for 洗濯代行 for laundry pickup and delivery.

And what class of hotel are you booking for the trip? Many business hotels offer self service washers and dryers but the rooms tend to be tiny. A full load would cost about ¥500 and takes about 1.5 hours (30 mins for the wash, 30-60 mins for drying).