These Oyster motoyaki taste even better than the restaurant in my opinion. I noticed a lot of recipes use miso paste in the mayo, but I did not find it is necessary when copying the restaurant flavor.
Preheat your oven to 400°F and position the rack in the middle position.
In a small bowl, combine all the mayo sauce ingredients, and set aside.
If your oysters are not shucked, put them on a plate and microwave for one minute until the shells open up. Use a knife to cut the connector muscle then remove the top shell.
Spread the mayo sauce evenly on each oyster then place them on a muffin tray. Fill the empty spots with a little bit of water so they don't overheat. Bake for 12-15 minutes until the oysters are cooked through and the mayo is golden brown on top. Enjoy!