I've found another great little French restaurant in central Tokyo. Cot in Nishi Azabu, just down from the Eneos near the crossing is a lovely French restaurant situated in a basement. What's good about the setting is that the floor plan is quite crooked which gives you plenty of privacy.
The food is excellent. On a recent visit, I was lucky enough to be taken here and we took the omakase menu, which allows you to sample various items that you can also order a la carte if you so choose.
Salmon, cream, apple and sakura leaf
Truffle pie (to die for)
Crab with flying fish roe
Foie gras and caramelised banana
Lobster and mac (my dining partner's, but I scored some)
Coconut blanc manger
Earl grey creme brulee