My experience at Mystic sands went FAR above and beyond what I was expecting. I was expecting a regular hotel experience, but it turned out to be far more. Mossy and her husband Maka are the caretakers for the hotel and they took care of us like family from the start. Maka is the driver for guests (including airport pickup/dropoff) and Mossy takes care of breakfast, activity/excursion bookings and pretty much everything else. The hotel has (I think) 5 regular rooms, plus a standalone large house with two king bedrooms. We booked a regular room but Mossy moved us into the standalone house since we were the only guests there. Throughout our stay, my friend and I interacted with Mossy/Maka many times. Mossy is like a mother and has an outpouring of love and kindness.
TIP - If you are there on a Sunday - go to church with Mossy and Maka. The language is Tongan but the experience was spiritual and heartfelt... and the singing is fantastic.
TIP - Remember Tonga is more about cultural experiences... There are not a lot of restaurants/bars/etc., so grab your own food at the market/store. Definitely make sure to have food/drinks purchased before Sunday, as stores are closed all day Sundays.