Looking for Oyster Bars- Izakaya style preferred, that serve different oysters, or at least fresh oysters are in their menu in Toyko that's not crazily expensive?
Google "Kakigoya" (or Oyster shack) and you will find them at many locations. Now is the season of "Iwagaki" (aka "summer oyster" or "Japanese rock oyster").
You would probably like Hamaguri in Shinjuku but it's always crowded . They sometimes have deals like 100 yens oysters. Not sure they have many varieties of oysters but many other types of shells for sure. It's izakaya style, not oyster-bar (western) style