After we booked the exp via Traveloka app, a Traveloka staff then phoned to confirm our booking. The staff said that the therapists will be 2 females.
On D-day, we went around 15 minutes earlier, and there was only 1 Meiso staff who is also the cashier. Not long after, a male therapist came. It was a bit strange, since the day before we were told that there would be 2 female therapists. And until we finished, there were only the 2 of them. Not sure what would happen if another guest came.