Who is John Macmillan from No Longer at Ease and what is their importance?

John Macmillan Obi Okonkwo's fellow passenger aboard the HV Sasa from England to Nigeria, Macmillan is an administrative officer in Northern Nigeria. When he slips and falls on a wet deck, Macmillan and Obi become fast friends. Each is twenty-five years old and both admire Clara Okeke's beauty.