This is the picture of the perpetrator of traffic accident who repeatedly neglected the process service from a district court via post office.
In Japan, court documents must be served by a post delivery man. And they will never do a service by placement even though the method is valid by laws. Nor will they do public records check or a neighborhood inquiry.
So if they fail to serve the document, the plaintiff has to do a site visit investigation for themselves. This is where we are kicked in as a PI.