Looking for help

Dear all, I am using the wisdom of crowds method for this puzzle. All you Sherlock and Sheila Holmes out there please help me. What is the case. We have bought two isolated plots in Soga or Higashiyama. To build a house in Japan you need access to a road. The former owner decided to sell it since he has not been able to locate the owner of the road. Even if you did not bother about the road it would cost a fortune to clear the plots in winter since they are not connected to a road that is being cleared in winter. My goal is to unlock the value of the land. Other plots are selling for 180k JPY per tsubo. We have thought of the following options: 1) Do nothing. Sooner or later there will be more developments in the area and we will be contacted by someone that buys us out. 2) Try to find the owner of the road by asking around, use FB and or put a sign on the land that says please contact me in Japanese 3) Try to find the owner of the adjacent plots and buy them out or combine some plots and sell them in one go. 4) Squat the area put a structure on it and wait till the owner of the road or the adjacent land contacts us and we work something out. Any thoughts or better solutions? There is a reward of 50k yen for the person that brings me into direct contact with either the owner of the road. Or the owner of the adjacent plot between me and the private road. Thanks a million. Danny