Here is the full list of all 32 Nya Nya Nya Girls achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
GameOut
Acane Aoi Hight
Akemi Hight
Ameli Hight
Any Hight
Asami June Isenami Hight
Ayano Hight
Katsumi Hight
Kitty Hight
Mizeki Hight
Mommo Hight
Acane Aoi Normal
Akemi Normal
Ameli Normal
Any Normal
Asami June Isenami Norma
Ayano Normal
Katsumi Normal
Kitty Normal
Mizeki Normal
Mommo Normal
Acane Aoi Easy
Akemi Easy
Ameli Easy
Any Easy
Asami June Isenami Easy
Ayano Easy
Katsumi Easy
Kitty Easy
Mizeki Easy
Mommo Easy
GameOn