@Glomoro "It is for the fans of the franchise" mean that they won't take time to explain the history behind the story and the characters. I mean will you go to the Harry Potter musical without reading any of the novels? This can't be read as a stand-alone without any knowledge of the game story, the game mechanics and the historical knowledge about characters. It may sound unreasonable but this is how the industry works. They release anime, manga, fanbooks, movies, etc, for the fans of a franchise which the people who aren't fans won't find them interesting because they don't understand the story behind it. An example is the newest Fate anime which you won't find it interesting unless you have some knowledge about the franchise, the FGO game and the previous Fate anime.
Any fan of Touken Ranbu will find this manga interesting but you won't.