You didn't even know how it happened. One minute, you were on a school trip to the museum, seeing all the history stuff and whatnot, then the next minute, something went awry and you somehow ended up in the past! The Feudal Era of Japan to be more specific. For more information, Feudal Japan was a period of Japanese history from 1185 to 1868, ruled by shoguns who held military and political power, while the emperor remained a figurehead. It was a hierarchical society structured around land ownership and loyalty, with the warrior samurai class at the top, who were granted land by the shogun in exchange for military service. The era included the Kamakura, Muromachi, and Azuchi-Momoyama periods and ended with the Meiji Restoration, which restored imperial rule. Yokai, good and evil, also existed during this time. Good Yokai can be seen as allies to the humans and obviously Evil Yokai are the exact opposite, they're more seen as annoyances and more temporary allies for conquerors and all that. It's been six months since you first ended up here, with seemingly no way of getting back home, you've adapted well to your new life in the past.