Air Carrier Captain reports being filed and cleared through areas S-1 and S-2 near RJAW. Once airborne the crew was rerouted after being informed by ATC that these areas are restricted.

Narrative

We were filed and received our clearance with no amendments from Clearance Delivery. Part of the leg took us through JDA S-1 and S-2. On the charts we noted it was not listed as a restricted or prohibited airspace. This airspace is near N25 E140; which was one of our filed points. While enroute we were rerouted; by ATC; to avoid this airspace. I contacted Dispatch and advised them of our reroute. Dispatch advised us that is was restricted airspace. This was the first time the word 'restricted' was mentioned. I referred to our paperwork and there was no reference of this airspace noted. The only mention of this airspace is in the navigation chart P (HI) 1-2 tab 5 under Training and Testing areas. It states; 'Aircraft flying for the purpose other than training and testing should not enter this airspace without prior coordination with Controlling Unit.' I assumed Dispatch had obtained permission to enter or else we wouldn't have been filed or been cleared through this airspace. Well Dispatch never obtained permission to enter this airspace. We flew the reroute with no other problems. This was a dispatch issue.