- Kirayoshi O'Brien was born shortly before the Dominion War and moved to Earth at the conclusion of the conflict.
- He spent his childhood all over the quadrant with his mother, visiting places as far-flung as Bajor, Alpha Centauri, and Cardassia Prime.
- “A Step Between Stars” - Lt. O'Brien is among the Enterprise-F crew assembled at Dyson Sphere Joint Command prior to launching the mission to rescue and assist Admiral Tuvok.
- “First Contact Day”: The player visits the bridge of the Enterprise at Utopia Planitia and meets with Kirayoshi O'Brien and the rest of his crew.
Kirayoshi is the second child of Miles and Keiko O'Brien and was born aboard Deep Space 9. He has an older sister named Molly. Dialogue in the mission "Sphere of Influence" mentions that the Chief Engineering Officer of the Federation's flagship, the U.S.S. Enterprise-F, is named O'Brien. According to Kestral's writings in Star Trek Magazine and her dialogue prompts to Dave Rivas for "Sphere of Influence", indicate that this is Kirayoshi.
- Kirayoshi O'Brien at Memory Alpha, the Star Trek Wiki.
- Kirayoshi O'Brien at Memory Beta, the non-canon Star Trek Wiki.
Leonard James Akaar • Borg Queen • Richard Castillo • Female Changeling • Damar Kahn • Dexa • The Doctor • Donatra • D'Tan • Gaul • Hugh • Icheb • Jhet'leya • Kahless • Harry Kim • Klag • Kortar • Laas • Lamat'Ukan • Leeta • Leskit • Madred • Leonard McCoy • Morn • Neelix • Kirayoshi O'Brien • Miral Paris • Ghee P'Trell • Q Junior • Alexander Rozhenko/K'mtar • Sirella • Montgomery Scott • Sela • Sessen • Seven of Nine • Spock • Taris • B'Elanna Torres • Tuvok • Naomi Wildman • Worf • Natasha Yar