Japan and China both read left-to-right, just like we do. While some traditional texts are written vertically with lines proceeding right-to-left, that doesn't really carry over to general UI conventions. A set of three horizontal images would typically be understood as proceeding from left to right, for instance.
Arabic and Hebrew, on the other hand, are primarily RTL, and this does carry over to UI conventions. Menus might be laid out differently there.
Arabic and Hebrew, on the other hand, are primarily RTL, and this does carry over to UI conventions. Menus might be laid out differently there.