"Third is Satō Masahisa, former JDF officer. Why is he so popular among LDP voters? Significance?"

Regarding Satō, this is his second time to be elected.
He was the commander of the GSDF deployment to Samawah in southern Iraq in 2004. He got a lot of good press coverage out of that. More recently I have seen him on Japanese TV talk/wide shows like TV Takkuru trying to discredit the DPJ's defense policies and more generally commenting on foreign policy issues.

I think Satō drew a lot of votes in 2007 based upon his Samawah exposure, but much of that memory has probably faded, and I doubt his TV appearances have fully compensated for that, so I am not sure if he fully qualifies as a "tarento." Nonetheless, he does have some significant name recognition and I think his service and loyalty to the LDP is appreciated by the party leadership. And I am sure he does garner a lot of votes from the SDF, their families, and SDF support organizations. That's a solid, if somewhat narrow, base upon which to run in PR.

On the other hand, I have a question: what is the relationship of the LDP to Zentoku and post master generals? I thought Koizumi had pretty well burned the LDP's ties to them. I don't remember exactly how far the DPJ and Kokumintou got in repealing postal privatization, but I believe the LDP has been opposing repeal. Hence, it would seem surprising if the LDP is recovering their ties with post masters.

Paul Midford