4 ideas
In 645 Prince Naka no Ōe and Nakatomi no Kamatari assassinated Soga no Iruka in the imperial palace, breaking the Soga clan's control of the Yamato court. The Taika Reform that followed nationalized land and people, moved toward a centralized bureaucratic state modeled on Tang China, and laid the groundwork for the ritsuryō legal codes. A palace murder thus became the founding act of Japan's imported model of state administration.
Japanese history is divided into eras named for where power sat, such as Asuka, Nara, Heian, Kamakura, Muromachi and Edo, rather than by dynasty. The imperial line stays nominally continuous while actual rule shifts among courtiers, regents, warrior houses and shogunates. Naming eras by capital or ruling headquarters therefore tracks where decisions were made, not who held the title.
An educational comic runs two channels at once: the panels turn historical figures into characters with faces, dialogue and motives, and the footnotes supply dates, terms and scholarly caveats. Readers remember the dramatized version far better than the qualifications, so the invented dialogue and imagined emotions tend to become the remembered history. The footnotes supply accuracy, but the story decides what readers retain.
When one accessible, multi-volume survey becomes the version most people in a country read in childhood, its choice of episodes, heroes and turning points becomes the shared baseline of national memory. Topics it dramatizes become common knowledge, and topics it compresses into a footnote largely drop out of public awareness. The authority of the standard text comes from how widely it is read, not from its scholarly standing.