In case you do not feel confortasble enough with calling, I still think it is possible to go there unannouced, especially early pm. Your chances will be good that it is not too busy.Chuck,
It is definitely better to call at least a day ahead if you can. If not, you can call once you get to the Gotanda Station if you have a phone as the website.
You can use a couple simple phrases such as:
Yoyaku asta hachio go hoon (85 minutes) dijobu deska?
She should reply Hai. (yes) If it is not so busy
Ni ji sanju pun (2:30 P.M.) dijobu deska?
She should reply Hai. (yes)
The above is an easy pronunciation and not exactly spelled out right.
Meiji, You are right about the photos as some are when the girls were younger. Still would like to get momma-san some day.
And yes, I wish I could get serviced by the Mama-san, friendly, playful, but that has not happened yet...