The group is led by PFC Desmond "Let's Go" McCaffrey, a veteran of the Guadalcanal campaign and the Battle of Okinawa with over 16 years of service in the Corps, yet he is repeatedly demoted from the rank of Sergeant.

McCaffrey, described as "a headache to the enemy, a migraine to the M.P.s" is incapable of behaving himself on leave due to his penchants for excessive alcohol consumption and hand-to-hand combat with people on his own side.

He converses with Private Pete Kono, a Japanese-American World War II veteran on a walkie-talkie to fool the staff of a respectable family hotel into believing the Marines are an undercover counter-espionage group working for General Douglas MacArthur, including having the hotel management give the Marines money for their expenses.

Other Marines in the group include: PFC David Chatfield, who McCaffrey hates because he is from a well-to-do Back Bay, Boston family.

Newt Levells is a young Texan who intends to meet a woman he has been corresponding with from his home town in Texas who was interned by the Japanese with her family during the war, but never returned to the US.