Green Sea Squirt
I have given up for now at trying to identify this green sea squirt. They are filter feeders. The side pores draw in the water and the top central pore is the outflow of the water.
I think that they are Atriolum robustum but they could be the similar species Didemnum molle チャツボボヤ. I cannot find any Japanese name for Atriolum robustum. It was fairly recently accepted as a species so many were probably identified as Didemnum molle チャツボボヤ in the past.