Thank you. Now it works.So I think I know why is this happening. Game expects a folder in Documents named "Bullet". In that folder there should be another folder named "3D少女カスタムエボリューション". In it there should be yet another folder named "save" and "settings.ini" file. If you don't have them, game will launch, but saving won't work. I checked this and the installer just copies the entire Bullet folder into Documents. I even tested on two different laptops and the results were the same. I hope this'll help anyone.
You need to use a japanese locale to save itI couldn't figure out how to save in this game
There should be at least one tutorial in the previous pages of this discussion, which tells you what folders you need to make and where as well as what files.I couldn't figure out how to save in this game
OMG THANK SO MUCH FOR TUTORIAL(>_<)For those who still can't save even with creating japaness folder name, it's cuz your computer do not recognize the language. Take a snapshot/screenshot using the "in-game camera", then you'll find a gibberish folder in "My Documents -> Bullet" (as suppose to "3D xxxx - the original japs folder" being created, which contain that snapshot.
Then put in the "save" folder and "settings.ini" in the gibberish folder mentioned in other comments.
The game will then auto save, and yes, there's no save button, it just auto saved as you exit the game