Here is the full list of all 100 Busty Hentai Mosaic achievements.
Without a bra
Without underwear, <3
Undressed!
Without outerwear
Outerwear
Koemi, 19
Emi, 20
Akem, 21
Maeko, 20
Utano, 22
Tsubasa, 21
Shiniqua, 19
Nishi, 22
Hisoka, 23
Kana, 19
Mikasa, 20
Rin, 22
Sugi, 24
Tora, 19
Katsuki, 20
This is B
This is U
This is S
This is T
This is Y
Without Outerwear
<3