Huge mess

It's kind of a long story buy please bear with me.

So i dated thig guy all trought college and things were great, i travelled to japan after graduation he cheated on me and knocked up a married woman obviously we broke up.He didnt take that well...

Fast forward 6 months and I moved to japan, my dads company have an office here and a partner and I know the man since I was 5, but I had never met his son.

At a dinner party I started talking to this guy and we just clicked.He is the partners son. Up to this point all was great his parents and totally approving and so are mine.He proposed and we went to my home country to visit my family and relatives.

Somehow the cheating ex found out all of this.

My fiance went back and I decided to stay a week longer.The ex sister calls my parents house to tell me he is going crazy, he sorta stalked me and my fiance had pictures of us,the house phone started to get some creppy calls.My parents live in a close gated area and he tried to get in.we got a restraining order.The ex father got involded and promise to do something with him.And i left so i tought it was over.

3 days ago my fiance got a package and a really wacko letter. No signature but who else would do that. The package was send from my home country but the address is fake.

Is there anywhere I can go and tell this hole story so that the crazy ex wont be given a visa? Can we get a restraining order against him in japan?

This is something you need to discuss with the authorities in both your home country and in Japan. The police, immigration authorities, lawyers, all would be better options than strangers on a message board.