If you've seen the anime, then this manga won't surprise you, as it basically retells the whole Katsugeki Touken Ranbu anime from start to finish, scece by scene, with a few changes. But it is those changes that make reading the manga worthwhile, even after you've seen the anime.

Compared to the anime, some of the scenes have been expanded and provide a better explanation to the situation or reasoning of the characters. There are also some minor and major changes compared to the story in the anime. An example of a minor change is Yagen and Mutsunokami fishing while watching over Sakamoto Ryouma (in the anime it's Yagen and Izuminokami). A major change happens in the second half of the manga:


All in all, if you've recently seen the Katsugeki Touken Ranbu anime and liked it and are looking for more Katsugeki related stuff, the manga is a good read. The changes and comparing said changes to the anime makes it interesting. The art is beautiful and the storytelling is good as well.