Dear Daisuke,
In Hamburg on a conference for investigative journalists last year I met Satoshi Kusakabe. Maybe Martin, Michael and Staffan remember this too. I am confident that he would be interested in talking to you about this. Please let him know that I told you this, he might remember our meeting in Hamburg. And please say hi to him for me!
Good luck and let me know if there's anything I can do or tell you about since we in The Netherlands recently started the Dutch version (with a lot of help from mySociety, lucky us) and are using the Pro version which could be interesting for journalists, like Satoshi.
Good luck!
Groetjes,
Liset