Gyoam Evan is a young man who works as the miller for the village of Tereo, operating the watermill located on its outskirts. He has black hair and black eyes, common features in the northern lands where he lives, and his build is slender yet sturdy from the physical demands of his labor. Despite his youth, he is responsible not only for grinding grain but also for collecting the village's taxes. His age is estimated to be between eighteen and twenty.

In terms of personality, Gyoam is enthusiastic and possesses a strong sense of curiosity. This is most evident in his keen interest in Kraft Lawrence, a traveling merchant, and the lifestyle of someone who journeys through the outside world. He is portrayed as having a friendly and approachable nature. Because of his low social standing as a miller, he is often treated with suspicion and coldness by the villagers of Tereo, a situation he has grown weary of. Consequently, his closest, and for a time perhaps only, friend and confidante is Elsa Schtingheim, the young deaconess who manages the village's church. Their relationship is that of secret lovers.

Gyoam’s primary motivation is to leave Tereo behind and become a merchant, aspiring to the freedom and adventure that such a life represents. He dreams of escaping the constant suspicion that plagues his current profession and of taking Elsa with him to start a new life. This ambition is tempered, however, by the events that unfold when Lawrence and Holo visit his village.

In the story, Gyoam serves as a key local contact when Lawrence and Holo arrive in Tereo seeking information. He is the one who initially greets them and later reveals crucial details about the village’s history, its fraught relationship with the nearby city of Enberch, and, most importantly, the existence of a secret pagan cave that holds clues to Holo's homeland. His role becomes central during the "poison wheat" crisis, where an accusation of sabotage threatens to destroy Tereo. Gyoam, along with Elsa, Lawrence, and Holo, works to expose the plot and save the village. His knowledge of the mill and the local product ultimately helps Lawrence devise a new economic solution for the village’s debt.

Gyoam’s most significant relationship is with Elsa Schtingheim. Their bond is the emotional core of his personal arc, and they are later married. While Gyoam is open and curious, Elsa is initially more reserved and pious, creating a complementary dynamic between them. His connection with Lawrence is also important, as Lawrence becomes a living embodiment of the merchant life Gyoam aspires to, and the two work together as allies during the village's crisis. Through these events, Gyoam undergoes a notable development. Beginning as a young man socially marginalized and dreaming of escape, he gains a greater sense of purpose and acceptance after helping to resolve the crisis. While his dream of becoming a merchant remains, the immediate goal of fleeing Tereo gives way to becoming more invested in its future.

Regarding notable abilities, Gyoam is skilled in the operation of a watermill and the practical work of grinding wheat into flour. He also possesses knowledge of the local political and economic dynamics between Tereo and Enberch, which proves valuable to Lawrence. Furthermore, as the village's tax collector, he has a functional understanding of the village’s financial system and obligations. His physical strength, born from farm labor, allows him to perform demanding tasks such as wielding an oxbow.