Holly Tanaka was born on the colony world of Minab in 2530. At age 20, the colony was attacked by the Covenant and the surface was glassed. Tanaka and a handful of others managed to survive, and they were forced to fight for survival on the partially glassed planet for three years without rescue. After finally returning to civilization, Tanaka enlisted in the UNSC Army, where she showed considerable talents, getting herself noticed and recruited into the Spartan-IV program. As a Spartan-IV, Tanaka’s first mission was on Requiem, where she fought during the Requiem Campaign against the forces of Jul ‘Mdama. Following Requiem, Tanaka continued her service aboard the Infinity, participating in Operation: ATHENA to attempt a recovery of the Janus Key. Though that operation failed, Tanaka was soon after reassigned to Fireteam Osiris, led by Jameson Locke. During her time in Osiris, Tanaka fought in several battles across many worlds, including Meridian, Sanghelios, and Genesis. As of late 2558, Tanaka is still a member of Fireteam Osiris.