RYU GA GOTOKU ISHIN
Ryu ga Gotoku Ishin (released in Japan in February 2014) is a spin-off game set at the end of the Edo period of Japanese history (known as the Bakumatsu period), a period when the Tokugawa Shogunate came to an end and imperial rule was restored (Meiji Restoration).
Sakamoto Ryoma is living undercover, with a false identity, as "Saito Hajime" in Kyoto. One year earlier, on the eve of the coup d'état of Tosa, Ryoma's foster father, the man who raised him, was murdered before his eyes. The only lead he had to discover who the killer was is that he used the Tennen Rishin style of fighting. This is a style used by the Shinsengumi, so Ryoma infiltrates their ranks, becoming captain of the 3rd Shinsengumi unit, in attempt to find the killer.
Big thanks to Kevin Debrabandere for creating a PDF for the entire Ishin guide. You can download the PDF version of the guide here. Please be advised that the PDF is outdated now, but still contains information for the whole game.