Ironically they’re filled with custard.
The marvelous flavour blew away my memory of what was actually served. I still know there’s sea urchin, tuna, and chawan mushi, amongst many other amazing things. Coupled with an intimate one-table-for-eight-people setting, they’re worth visiting if you’re near Ginza.
It’s a popular chain restaurant in Japan, but still worth having lunch/dinner there at least once. Some are open 24hrs in case someone needs a quick beef fix! XD
Very good nevertheless. Check them out!