Petenshi Luca to Kuroki Maken

In a world where sorcery is forbidden and those who expose it face execution, Luca, a young man who presents himself as a traveling con artist, possesses the outlawed power known as "mana," which is considered the "devil’s magic." He conceals his ability and embarks on a journey to locate his father’s enemies and a grimoire inherited from his ancestors. Along the way, he encounters a dog with black and white fur, which he names Saro. Saro has the secret ability to shift between a monster and a human form. Together, they begin a fantasy adventure in a medieval renaissance-style setting.