Yuri Kitayama 
Seirei Gensouki: Spirit Chronicles (Manga) Volume 6 [EPUB ebook] 

Rio’s journey finds him stumbling upon a village in the Yagumo region, where he is welcomed into the home of Chief Yuba and finds friendship with Sayo and Ruri, two girls close to him in age. Suddenly, the king and queen request Rio’s audience in the capital, where they discuss the secret of his parents’ origins, his birth, and a tragic past that has made him an arbiter of vengeance.

As time passes and Rio prepares to leave the village, Sayo’s feelings morph into something more complicated—but will she be able to articulate them before their time together is up?