Japan has the most beautiful manhole covers, and there have been several art projects and books to document them.
Shimonoseki is famous for their blowfish, so it is logical for them to use it as a logo for their city.
I kind of regret not trying fugu* when I was there, but I have to admit that I am particularly squeamish when it comes to fish and seafood in general. I cannot say why I can eat mammals, but cringe at fish—my husband teases me that somehow I feel it is cannibalistic, as I am a Pisces. (^_^) [I’m not a believer in astrology, but I do identify with the symbol of two fish swimming in opposite directions!] Probably it has more to do with growing up in the Midwest of the U.S. and not really being exposed to (fresh) seafood. I did meet several Japanese people who also did not like seafood, so it was nice to know I’m not a complete freak of nature.
*While it is famous for containing poison, eating Fugu is not dangerous when it is prepared properly. The people who die from it each year are either completely ignorant of what they are doing, or perhaps fully aware of what they are doing (they prepared it themselves). If you eat Fugu at a restaurant (or the fish market in Shimonoseki), they will have removed the part of the fish which holds poison. It is very popular, and many people visit Shimonoseki to enjoy Fugu. If you are ever there, I would recommend trying it, even if I personally chickened out! (^_^)