Check this out: http://www.jma.go.jp/en/gms/largec.html?area=6&element=1&tim...

edit: The largest image resolution seems to be 800x800 (well, 800x815, with the attribution footer). I wonder if the new satellite's imagery isn't part of this feed yet? I hope that's the case, because it would be incredibly cool to be get such high-res images.