MEOW_IRL

No, you're right.

Some will edit in little numbers or arrows to indicate the order, or even edit the panels into western order (though that then confuses the hell out of those of us who have learned to read them in the original layout, which kicks in whenever we see that style).

On some, the sequence in the panels makes the order very obvious, but that's not the case here.

What I would have done in OPs place, is just split the two columns and move them atop each other, so it's all top to bottom. That'd have made sense to everyone.