Obi's full name is Obiajulu, which in Ibo means "the mind at last is at rest." He feels impatient with the traditions and frequent censure of village life. However, he also feels alienated from his father's Christian path toward modernization. Somewhat willful, Obi was sent to England to study law, but he switched to studying English literature instead. He is morally upright and refuses to take bribes. He believes that corruption will end in Nigeria when the older generation dies out.
Clara is initially standoffish when she meets the awkward Obi Okonkwo, who is flummoxed by her beauty. Once they start dating, she enjoys popular culture, such as movies and dancing, more than he does. Like Obi, Clara is one of the Ibo (also spelled "Igbo"), a people of Nigeria. She studies in England at the same time as Obi, and she becomes a nurse. She is also an osu, a member of a sacred but outcast, unmarriageable caste of the Ibo people. She believes that, because of her caste status, she and Obi have no future.
After her death Obi remembers his mother, Hannah, as a woman of action. She got things done. When she was a young bride, she boldly killed a village goat that had been pestering everyone. No one else dared because the goat was dedicated to a god. Hannah remains attached to traditional Ibo ways. This initially makes her seem like the softer, tenderer parent. When Obi is embarrassed at school because his Christian father has not taught him any folk tales, Hannah teaches him one on the sly. But her traditional views lead to a crisis for Obi when she refuses to countenance his marriage to Clara.
Isaac Okonkwo is so staunchly Christian that he refuses to tolerate many Ibo customs. This can make him seem harsh and judgmental, particularly to his son Obi. However, Isaac became a Christian in defiance of his father, who cut him off for his beliefs. Isaac feels that Obi can never really understand Christianity without having had that experience of persecution.