Skribulous said: The confusion comes from the knowledge that there is no ocean in Gensokyo. Yet.
There is no ocean at the present, but in the past an ocean covered much of the world; Japanese creation myths have the islands arising from the ocean. Just like a sea took up much of the North American continent.
Its presence...Shin.
Wikipedia article is here: "http://en.wikipedia.org/wiki/Shen_(clam-monster)"Why?It's an ocean youkai.
Hop!It's a clam youkai, but...That shape... Could it be?...confuses the senses.Why is it in Gensoukyou?