It is a pain. Right now I have requirements:
Raquel: 4 mementos (2/4)
Leilani: 3 mementos (0/3)
Yasu: 2 mementos (1/2)
So I need to find 6 mementos in Gatcha. I used about 30 regular, 8 favor and 4 luxurious and there was not even one...