When written horizontally it is now left to right but earlier you would see horizontal right to left. But vertical was preferred especially in the past.

You can see horizontal train stop signs written right to left in “In This Corner of the World” anime. Today all signage seems to be left to right.

[edit] The history section in Wikipedia explains that this was a postwar script reform. https://en.wikipedia.org/wiki/Japanese_writing_system

Horizontal right to left is an edge case of vertical writing with one character tall columns.