I too have looked all over... in, out and around the temple and can't find this oyster. Of course, you can't look near back stairs because you are pulled into temple when you get close to the building, but i certainly looked around the front stairs and looked in every inch inside the building.
Can anyone help with the Yoshito Temple Oyster? Given that this is only the third one I'm looking for, I suspect I will run into this with others too. Is there a guide that lists where each is (I've seen this with the MB cats and with the WC Smiths, but have not seen anything like this for the oysters).
I had same problem, probably spent an hour looking around the temple. I finally found it. It is not named well. I found it after I gave up and moved to the next one. Head towards the Village of Sorrow. The Yoshito oyster is on the way, near stairs before you get to the VOS.