Who were the main characters of The Teahouse of the August Moon

The Teahouse of the August Moon is a comedy in three acts written by John Patrick and adapted from the 1951 novel by Vern Sneider. It became one of his most popular works, winning him the Pulitzer Prize for drama in 1954, and even inspired the popular movie of the same name starring Marlon Brando and Glenn Ford.
The play takes place on the island of Okinawa during the American occupation of Japan in the aftermath of World War II. In it, the author satirizes the inability of the American military forces to understand Japanese culture and their ridiculous attempt to Americanize it, through a plethora of humorous scenes. While it gained critical acclaim both from theater critics and audiences in the time it was created, it would probably not be that well-received today because of its obvious stereotypical presentation of Asian culture and tradition.
The two main characters in the play are Captain Fisby and Sakini.
Captain Fisby is described as a good-looking man in his late twenties, eager to please and always wanting to make a good impression on others. From his office in Tobiki, Fisby is assigned to implement "Plan B," or to teach the locals of the "American way," establish capitalism and a local democratic government, give democratic lessons, and build a schoolhouse. But, in his attempt to do so, he gets a bit of a culture shock, and instead of executing his given task of familiarizing the Japanese with all things American, he himself begins to slowly understand and appreciate Japanese culture and tradition and becomes rather accustomed to it; he also starts to accept and appreciate his own true character.
Although reluctant to accept the decision of the new government to build a teahouse for Lotus Blossom (a geisha given to Fisby as a gift by her father), he later agrees and gets a business deal out of it by selling brandy. Because of his fast accommodation and eager-to-please nature, he is accused by his commanding officer, Colonel Purdy, of "wasting military supplies for making alcohol" and, most importantly, "not turning the locals American" as per agreement, and so the Colonel threatens to destroy the teahouse. But, the Colonel is outsmarted in the end, everyone is forgiven for their "wrong doings," and Fisby is painted as a hero.
Sakini is the Japanese interpreter for the American military. Because of his unique and peculiar physical appearance, he is said to be of

any age between thirty and sixty. In repose his face betrays age, but the illusion is shattered quickly by his smile of childlike candor.

He’s described as a calm, clever man, but at the same time rather simple-minded and slow-witted. He’s the picture-perfect example of Asian stereotypes present throughout all of Western culture. Sakini is the one who acquaints Fisby with Japanese culture and serves as a narrator in the play, guiding the audience through the plot, setting up the imagery, and explaining historical and cultural facts via various monologues and dialogues. With the help of the villagers, he’s the one who outsmarts Colonel Purdy in the end, and he is the first one to raise a glass in honor of unity to him and the rest of the American military personnel, showing his wise and forgiving nature.
https://www.encyclopedia.com/arts/educational-magazines/teahouse-august-moon