Seirei Gensouki: Spirit Chronicles (Manga): Volume 10 - Futago Minaduki, Yuri Shibamura, Mana Z.

When Rio discovers that Professor Celia is about to marry the contemptible Charles Arbor, he infiltrates the royal castle to confirm her feelings directly—unfortunately, it’s all too clear to him the marriage will not be a happy one. He offers to help Celia escape, but with the threat of the Arbors’ retribution toward her father looming large in her mind, Celia rejects Rio’s help and resigns herself to her fate... Knowing he has few other options to liberate his beloved professor, Rio hatches a plan that will pit him against the might of an entire army. Will his bold ploy manage to obstruct Celia’s unholy matrimony?