Here is the full list of all 100 Busty Hentai Mosaic achievements.
Without underwear, <3
Undressed!
Without a bra
Without outerwear
Outerwear
Utano, 22
Maeko, 20
Koemi, 19
Emi, 20
Akem, 21
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