He probably means
this drama.
Every year, NHK has a year-long historical drama, and Shinsengumi is this year's. AFAIK, it's very popular and triggered a Shinsengumi fad (not that it's all that difficult to start a fad in Japan...). It airs every week, though, so it runs somewhere around 50-2 episodes (then they do a huge summary recap episode at the end of the year).