For NHK Taiga drama some of them are available on video in a condensed form
( remember they are originally 49 episodes)
Try this site
http://www.amuse-soft.co.jp/ but be warned they are only in
Japanese and are very expensive. If you are still in Yamaguchi Ken I am sure
you can find most of them at any big video rental shop.
Taiga Drama has been around since 1962. of the forty plus drams the ones you
might be interested in are;
Kashin (1977) this was about Choshu in the Bakumatsu period
Tobu ga yuku (1990) Saigo Takamori
Shishi no Jidai (1980) Aizu-Wakamatsu
Some other bakumatsu Taiga dramas not available on video are Hana no shogai
(II Naosuke) Ryoma ga Yuku (Sakamoto Ryoma) Katsu Kaishu, and Tokugawa
Yoshinobu.
In addition to the year long Taiga drama NHK also does a 2 hourspecial for
shogatsu. 2000 was Tenkoku no Yume about Yoshida Shoin and Takasugi
Shinsaku.
On other channels there have been a plethora of jidai gekis about the
bakumatsu period. I have about 130 titles courtesy mostly Seimon Jidai Geki
Channel. There have been many dramas about Takasugi Shinsaku, Yoshida Shoin,
Kiheitai, as well as the shinsengumi, Sakamoto Ryoma, Goryo kaku etc etc.
Currently the Family Channel has been airing Tenno no Seki from 1970. This
is all about the period the Black ships on.