The Vexations of a Shut-In Vampire Princess, Vol. 3 — Kotei Kobayashi

Can a murderer be a pacifist?
Komari has finally earned a vacation, and she's soaking it all in at a beach resort. That's when Nelia Cunningham, a commander from the Gerra-Aruka Republic, appears before her with an outrageous proposal: Together, they'll take over the world.
At the same time, a commander from the Heavenly Paradise named Karla Amatsu shows up and offers Komari the exact opposite proposition: Together, they'll usher in world peace. Before long, the two nations' clashing agendas drag the whole world into war! Rudely pulled from her summer holiday, Komari holds the key to the conflict in her hands. Without it, the war may never end.