Game Cheats:
Unlock Secret Characters
The following hidden characters are unlocked by completing the corresponding task.
Momo:
Buy the 'Goldfish' from the store and then attempt to discard them during the day.
Celeste:
Give Kyu your 'Dirty Magazine' after unlocking her to gain the 'Strange Object'. Attempt to give this to someone at the beach during the night.
Venus:
Have every other non-secret character spend the night over.
Kyu:
Have a woman spend the night over.