Monster Strike Anime: Masamune - Shimei no Akaki Yaiba

In a near-future nation stripped of much of its independence, Masamune leads the Mikado family's guards and accompanies the Mikado to a peace conference meant to stabilize the country. Before peace can take hold, the militant Mitsurugi Party under Iwakura launches an uprising and turns the capital into a battlefield, placing the Mikado himself at the center of the conspiracy.

Masamune succeeds in helping the Mikado escape, but the rebellion brands them as enemies and sends pursuers after them. With the capital lost and the truth buried beneath the coup, she heads toward her home village of Shusui, carrying both the duty of protecting the Mikado and the red blade tied to her family's mission.