The restaurant in Kill Bill is based on “Gonpachi” in Nishi-Azabu. Although 99% of the fight scene was filmed on a set apprently one or two scences were really filmed there.
You’ve got to love Tarantino!!!

It is not too far from Roppongi subway station to walk. Take Roppongi-dori street toward Shibuya direction. The restaurant is at the foot of the down slope on your right at the corner of Nishi-Azabu intersection. I’d say it might be a 10 minutes walk or so.