Merc Storia: Mukiryoku no Shounen to Bin no Naka no Shoujo

Merc Storia takes places in a world where humans and monsters coexist. The protagonist, Yuu, is a healer apprentice and possesses the ability to tame monsters. In a quest to regain the memories of Merc, a girl confined in a bottle, the pair embarks on a journey. (Source: MAL News)