Our Last Crusade or the Rise of a New World, Vol. 5 (light novel) — Kei Sazane

UNDER THE SAME STARSTwo sisters with two clashing impressions of the same boy: Sisbell would do anything to get Iska to be her ally, while Aliceliese sees him as a worthy opponent, regardless of their duties or convictions. As part of a deal with Sisbell, Iska is required to serve as her guard until she returns to the palace. None the wiser about this pact, Alice desperately races around the nation to locate her younger sister before the other families can target her again. When Alice spies Sisbell and Iska linking arms in the Sovereignty, her chest starts to ache for reasons unknown…