If you are talking about page order or panel order (in something like manga), those go right to left. More specifically, manga panels follow the usual western comic book panel order, except with left and right flipped.
However, when it comes to the actual text (regardless of the medium), it is always written either top to bottom or left to right. There is no right to left text writing in japanese. This isn't arabic, where text is indeed written right to left.
Again, even in the scenario you are describing, it is right-to-left when it comes to organizing columns/page layout (just like it would be with manga), but the text is still not right-to-left. It is top-to-bottom text vertical columns going left-to-right horizontally.
There is not a single instance I can think of where the actual text in Japanese would be read/written horizontally right-to-left.
Arguments about modern Japanese text layout is beyond the scope of my original comment, and I don't think it's meaningful to discuss it anyway. Those who know and use Japanese know, and those who don't, don't need to know.
However, when it comes to the actual text (regardless of the medium), it is always written either top to bottom or left to right. There is no right to left text writing in japanese. This isn't arabic, where text is indeed written right to left.