User:WT111/Sea of Fertility
The League of the Divine Wind (神風連 Shimpūren) and its rebellion in Kumamoto in 1876 is an actual event: names have not been changed, and the event unfolded much as described in the book. However, the story-within-a-story and its author "Yamao Tsunenori" are a work of fiction written by Mishima, being apparently loosely based on League of the Divine Wind: Story of Tears of Blood (神風連血涙史) by Ishihara Shiko (石原醜男).
Isao's conspiracy is very loosely based on the League of Blood Incident (血盟団事件 Ketsumeidan Jiken) of 1932. Iinuma bears some resemblances to the League's leader Nissho Inoue (although he was a fervent Buddhist, not Shintoist) and "Busuke Kurahara" may be based on Baron Takuma Dan, head of the Mitsui zaibatsu and the League's 2nd victim. That's where the similarities end though: the League used guns, not swords; Takuma was murdered before their arrest; and and none of its members committed suicide.
Temple of Dawn
The Decay of the Angel
The following are all within the city limits of Shizuoka, which has absorbed Shimizu: