The historical context of this anime is indeed demanding - you will have to wiki some names and battles - but the artistry and the theatrics employed are so great you want to keep watching the play until the right names come about. It's best lays between episodes 1 and 13 (felt some disorientation in the argument after that point, like they were trying to pull up several storylines that would somehow converge in one single point in a map). All the characters are immensely valuable, particularly the secondary ones like tayu, hijikata's right arm, nakaya jubei and the 4 english elite warriors that, as theycome, bring the story closer to us.

Hijikata's journey north towards honor is sublime and kanna's descent operates as an inverted journey into despair. We are not given the answers for all the questions this anime brings about but it is fine: there is an element of surreal that allows for it to happen.
Technically, this production has very high standards both in the drawings as well as the animation itself. The cenarios are very much in harmony with the action and the characters are very dynamic.

If that wasn't enough, the soundtrack is simply breathtaking.