This page is in English but, somehow, the blurb you see below came out in Japanese. At any rate, the blog talks about how "bicycles can be taken on trains of Kumamoto Electric Railway for free" and how at "Kita Kumamoto Station where I changed a train I could finally see the 'greed frog'!!", etc.
http://kumanago.jp/en/blog/2013/06/26/the-train-with-wrap-advertising-of-keroro-gunso-so-called-a-green-frog.html
Blog Kumamoto Nagomi Tourism Site
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