Yuri Kitayama 
Seirei Gensouki: Spirit Chronicles (Manga) Volume 10 [EPUB ebook] 

When Rio discovers that Professor Celia is soon to marry the contemptible Charles Arbor, he infiltrates the royal castle to confirm how Celia feels directly—unfortunately, it’s all too clear to him the marriage will not be a happy one. He offers to help her escape, but with the threat of the Arbors’ retribution toward her father looming large in her mind, Celia rejects his 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 military might of an entire army. Will his bold ploy manage to obstruct Celia’s unholy matrimony?