The history of House Yamazaki’s civil war, which took place from April 17th, 63,201 LY to January 30th, 63,203 LY was a long and brutal 21 months in the history of the Moon Kingdom. When Princess Megumi IX Yamazaki declared a state of civil war against her infamous and outright despised biological mother, Princess Rin I Yamazaki, the Great Houses of the Moon Kingdom all declared within the first three hours which side they would fight on.
Due to Princess Megumi IX Yamazaki making friends with the other Great Houses while she had the chance to without her biological mother finding out, House Tenou, House Hosokawa, House Kaiou, House Hino, House Kaiou, House Meiou, House Tsukino, House Chiba, House Takeuchi, House Mizuno, House Aino, House Kino, House Tomoe. House Osaka, and House Tsuruya all declared their support for her. House Tsuruya was one of the first to declare their support due to Megumi’s boyfriend, Prince Mamoru Tsuruya, was the brother of the reigning Princess Aoi V Tsuruya. The only houses that declared their support for Princess Rin I Yamazaki were House Yamamoto, House Shimada, and House Hagino; three houses who ruled their territories as if it was a totalitarian dystopia.