Ahhh....this is the "miracle fru-tsu" restaurant. Probably a bit more posh than the tacky amusement park in Ikebukuro which, AFAIK, is the only other place in Tokyo to get this stuff.

Needless to say, I went to the tacky amusement park, which also has "gyoza city" included for the same admission price (Y300/person to get in). Last time I was there, there also was a little floor show with dancing people in cute animal costumes.