I've been to this restaurant a couple times and I've had a really good time there. For supper it's a bit expensive, but they have a nice menu for lunchtime on weekdays and they accept Ticket Restaurant.
Better to make a reservation in advance, specially for lunch, the place is quite busy!
I highly recommend the Macha Tea, it's delicious!
The only con I find is that they take quite long to serve, I guess they don't have enough staff, so better don't go there if you don't have plenty of time. I didn't find any problem at dinner time, by the way.
Cons: They take quite long to serve.