Hi Akihiro-san:
I know where Nikko Ko-en is, I have been there to see the fall colors of the leaves on the trees. Spectacularly beautiful.
You mean there really is no dedicated CL field anywhere in Japan, even with the great flyers you have?? And you are flying out of a dry riverbed? I am almost embarrassed to say that I have a dedicated CL field about a three-minute drive from my home near San Francisco, in a city park. It is not perfect, but it sure is convenient. No RC or anything else, just CL. I Will be there tomorrow morning.