Why are manga read from right to left? Has it always been so? Why are manga read right to left? Has it always been so? Are there any exceptions?

(Flipped mangas are excused from this question.)
The traditional Japanese written language goes from right to left.
Books in Japan tend to start from the &quot;right-most&quot; side.  It's only natural that manga publications follow the same format.

Traditionally, Japanese is written in a format called tategaki (縦書き?),
which copies the traditional Chinese system. In this format, the
characters are written in columns going from top to bottom, with
columns ordered from right to left. After reaching the bottom of each
column, the reader continues at the top of the column to the left of
the current one.
Modern Japanese also uses another writing format, called yokogaki
(横書き?). This writing format is horizontal and reads from left to
right, just like English.
A book printed in tategaki opens from what a Westerner would call the
back, while a book printed in yokogaki opens from what traditionally
in Japan would have been considered the back.
—Wikipedia