Unlock Nani 1:
Put in the password WQBLD5

Unlock Nani 1+2:
Put in the password awWl2hx

Unlock Nani 1+2+3:
Put in the password HtrkwtI

Unlock Kumiko 1:
Put in the password sMU99R0

Unlock Kumiko 1+2:
Put in the password WsKV7z2

Unlock Kumiko 1+2+3:
Put in the password XaoWCBZ

Unlock Saori 1:
Put in the password vkz2OBu

Unlock Saori 1+2:
Put in the password tYU2TEb

Unlock Saori 1+2+3:
Put in the password t9GJ6Ol

Unlock Saori's Ending:
Put in the password t9GJ6Ol