Kostya
He is the protagonist of the story. Kostya is a young university student around who's experience the plot revolves. With no previous acting experience, he enrolls in an acting class taught by the master, Tortsov. His transformation into an acting enthusiast is a reflection of Stanislavski's own experience as a young man.
Tortsov
Tortsov is the director, the world's leading authority. He teaches the Stanislavski method, though not by that name in the book. In his reserved manner, he inspires his students to fully embrace his teachings, as if they were sacred scriptures. He is a man that demands respect. Doubtless his experienced wisdom reflects how Stanislavki feels about his own work throughout his career, the authority which he has gained.