Fermi Amati is a young merchant who appears in the town of Kumersun. He is a fishmonger by trade and a member of the Rowen Trading Guild, the same merchant association as Kraft Lawrence. Physically, Amati is an adolescent of about fifteen or sixteen years old, with short blonde hair and blue eyes. He typically wears a large black cape over his casual attire.

In terms of personality, Amati initially comes across as cheerful, friendly, and helpful. He is an ambitious and clever young merchant who has achieved a degree of success at a very young age, owning three wagons. However, beneath this pleasant exterior lies a tendency to act rashly and impulsively, particularly when his strong sense of chivalry or justice is triggered. He is prone to forming quick, passionate judgments about a situation, especially if he believes someone is being treated poorly. This combination of ambition, youthful confidence, and a romantic nature drives his actions.

Amati's primary motivation in the story is his infatuation with Holo. He becomes instantly smitten upon meeting her and quickly develops a romantic obsession. His goal becomes to free Holo from what he believes to be a debt to Lawrence and then to propose marriage to her. This desire is fueled by a misunderstanding, as he accepts the elaborate ruse that Holo is a traveling nun indebted to Lawrence. He sees himself as a heroic figure rescuing a damsel in distress, and this perceived noble quest justifies his bold, competitive challenge to Lawrence.

Within the narrative, Amati serves as a rival to Kraft Lawrence. Their relationship begins amicably as fellow guild members, but it quickly becomes hostile when Amati misinterprets Lawrence's relationship with Holo as exploitative. He publicly challenges Lawrence to a merchant duel, proposing a binding contract to pay off Holo's fabricated debt of one thousand silver coins. This event is the central conflict of his appearance, testing the bond between Lawrence and Holo. His relationship with Holo is one of unrequited and misguided affection. While he is devoted to her and wishes to shower her with expensive gifts, Holo is not only uninterested but also becomes angered by his assumption that she is a helpless victim. She finds his treatment of her as a vulnerable girl to be rude to both herself and Lawrence.

Amati does not undergo a positive development arc within the story; instead, he experiences a decisive downfall. Convinced of his successful plan to raise money through pyrite speculation, he eagerly accepts a credit sale contract offered by Lawrence. This was a strategic trap orchestrated by Lawrence and Holo, who worked both independently and together to manipulate the pyrite market. Ultimately, the price of pyrite crashes, causing Amati to suffer enormous financial losses. He is humiliated in public, loses the bet and his right to propose to Holo, and is left financially ruined and emotionally devastated, realizing he was deceived by the very person he was trying to "save". Despite his defeat, it is later mentioned that he eventually recovers to live a happy life.

Amati’s notable ability lies in his skill as a merchant. He is ambitious, capable, and well-regarded in his trade, successfully speculating on the pyrite market. His cleverness and access to capital make him a credible threat to Lawrence’s relationship with Holo. However, his judgment is clouded by his passionate and impulsive nature, which ultimately proves to be his greatest weakness. His talents as a merchant are no match for the combined cunning and experience of Lawrence and the wise wolf Holo, who are able to exploit his rashness and romantic naivete.