In Modern Tenjiku Shogi it slides vertically. This is another contested rule issue. The first western publication was by George Hodge's TSA ("The Shogi Association") and gave a vertical slide. IIRC it seems that only two historic sources are known that describe Tenjiku Shogi, and that one of those contains an inconsistency between the text and the accompanying image. (The text says vertical, the image and the other source consistenly say horizontal.) So it is 3 vs 1, as well as that it seems more likely to err in a text than in a picture. The best argument for a vertical move seems to be that "there could be yet undiscovered sources that also state it moves vertically".
But the modern rules do not claim to be the historic rules. I used the modern rules for the Jocly implementation so it could participate in the correspondence championship.
In Modern Tenjiku Shogi it slides vertically. This is another contested rule issue. The first western publication was by George Hodge's TSA ("The Shogi Association") and gave a vertical slide. IIRC it seems that only two historic sources are known that describe Tenjiku Shogi, and that one of those contains an inconsistency between the text and the accompanying image. (The text says vertical, the image and the other source consistenly say horizontal.) So it is 3 vs 1, as well as that it seems more likely to err in a text than in a picture. The best argument for a vertical move seems to be that "there could be yet undiscovered sources that also state it moves vertically".
But the modern rules do not claim to be the historic rules. I used the modern rules for the Jocly implementation so it could participate in the correspondence championship.