How to manage luggage while visiting sites

Does doing Sam's New Golden Route require that one has their luggage with them at all times? Where does one put luggage while visiting sites prior to checking into a Ryokan? We will be in Japan for two weeks.

I don't understand your question. Are you trying to bring you luggage with you everywhere you go or asking if you can just store it somewhere? I mean, if you're staying in a hotel, just store it there?

If your travel plan is like this

Day 1 Stay in Ryokan A.
Day 2 Train/bus travel to Ryokan B. Stay in Ryokan B.
Day 3 Train/bus travel to Ryokan C. Stay in Ryokan C.
Day 4 Train/bus travel to Ryokan D. Stay in Ryokan D.
Day 5 Train/bus travel to Ryokan E. Stay in Ryokan E.
Day 6 Train/bus travel to Ryokan F. Stay in Ryokan F.
Day 7 Train/bus travel to Ryokan G. Stay in Ryokan G.

There are two ways to solve your luggage problem.

1. Travel light. Just carry two days of clothes and wash them in your Ryokan or hotels every two nights. I think 3 kg backpack is enough. No need to carry nightware, towels, etc. In this way you can minimize your bag(s). The backpack is useful for carry your gabbage like PET bottles, wrappers etc.

2. Send your luggage using Ta-Q-Bin from Ryokan A to C (or D) and C to E (or G). If you send it in the morining of Day 1 your will normally receive it on Day 3 (ask the clerk at the Ta-Q-Bin office). As for writing the address, prepare the address in Japanese (I think you can get at somewhere on the net and print it out) and ask the Ryokan staff to write it.

Actually you can do the mix of 1. and 2. I am a Japanese, and do the mix by myself. Don't worry. Enjoy your trip!

Two other options:
(1) Use coin lockers. Most train stations have them.
(2) Go to ryokan/hotel and ask them to hold the luggage until you check in.

I just looked at Sam's new golden route, looks busy. I agree with Frog (we use carry on only for a 2 week trip, no drama), though if you are going to be changing accom nearly every day it will be harder to wash clothes unless you go to a coin laundry.

Usually you can leave luggage at a ryokan before you check in, so go to a town, straight to the ryokan, check in bags them go off to do stuff. Otherwise it would be a matter of leaving stuff at coin lockers at the train stations.