Selling Fish From Boat
This guy had at least 3 distinct types of shrimp for sale on his boat. He was operating under a bridge and would send the seafood up to the bridge deck using his long handled net.
Oden Stand
Oden is basically seafood/tofu/stuff on skewers served from a common broth - it's common to see in 7-11's. This stand was at the exit to a subway station. One piece (octopus wrapped in Tofu) was enough for David and Andrea to get a taste.
Ascidians - Halocynthia roretzi
The internet has come through - apparently they are ascidians - specifically Halocynthia roretzi. Ascidians are sea squirts — hermaphrodite marine invertebrates that live in shallow ocean waters, and which are thought to exhibit characteristics of the evolutionary ancestors of chordates and vertebrates.
(Thanks goes to Karen Sanamyan at ascidiacea.com/