The Japanese prosecutors pulled some pretty outrageous stuff, like demanding that he have no contact with his wife while under house arrest.
Stunts like that are what you pull when you've got no case and you just want to bring someone to the point where they'll plea to any deal proposed in order to just make it stop. It happens in the US as well, but usually not to those with a public profile.
The FBI even has a word for it: bumperlock - when they don't have enough to make a case, so they disrupt someone's life with overt surveillance and hope that it drives them to actually break the law.