Here is the full list of all 32 Nyasha Beach achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Ayana Hight
Naomi Hight
Yuri Hight
Tsukiko Hight
Choko Hight
Hana Hight
Nami Hight
Mizuki Hight
Misaki Hight
Akiko Hight
Ayana Normal
Naomi Normal
Yuri Normal
Tsukiko Normal
Choko Normal
Hana Normal
Nami Normal
Mizuki Normal
Misaki Normal
Akiko Normal
Ayana Easy
Naomi Easy
Yuri Easy
Tsukiko Easy
Choko Easy
Hana Easy
Nami Easy
Mizuki Easy
Misaki Easy
GameOut
Akiko Easy
GameOn