There are lots of rules relate to japanese funeral. The ceremony has to be held on specefic day or must avoid certain days. Certain ceremonies must be held before certain day and so on.
Here is one that I think quite interestig.
After you vist your ancesor’s graveyard, on your way home, you must change the way. In other words, you shouldn’t take the same way that you took when you came. Otherwise you’ll bring someone who’s not belonging to this world to your home.
And….Don’t look back over your shoulder, even you are taking a different way. Maybe someone is still looking for you.