Hey there,
I start this thread just to share a website about parking information. You will be able to find FREE parking here . And in terms of FREE, most of them are in shopping malls or supermarkets, which means that you can buy something and then get FREE parking for some hours. And also there are some parking-meter locations in the website, which you will be able to enjoy FREE parking under some conditions. Furthermore, you can switch to google map navigation just by a simple click in the parking lot info box. For now it supports only Japanese, feel free to have a try!