Current as of update 024. May contain spoilers.
The Alliance for a Free Jupiter
The crew of the AIJ Esther Strova
Himegami Kana: A pilot for the AIJ serving on the. A former pirate, originally from Ganymede. Has a nosy, oily air that makes people think she's up to something. The protagonist.
Black, Azara: A pilot for the AIJ, Kana's and Kitty's squadmate, and Kitty's lover. Originally from a backwater station, where she joined the local militia. Talkative and utterly without shame.
Booker, Sara: First officer of the Esther Strova. Very no-nonense. Dislikes Kana.
Goodwell, Dr. Manjinder: Medical officer of the Esther Strova.
Leski, Jacek: Captain of the Esther Strova. Boisterous and energetic.
Lý Thị Cam: A pilot for the AIJ, Jay and Ryan's squadmate. Originally from a family of salvage operators, has a fascination with machines and military hardware and a talent for mechanics. Quiet and earnest, easily flustered.
Monserrato, Sunny: A pilot for the AIJ, Kana and Azara's former squad leader. A deserter from the Divine Navy, diligent and straight-laced. Was killed by Divine Navy Ensign Tanaka Mari.
Ohanian, Nazaret: Communications and mecha control officer for the AIJ. Kana's friend. Easygoing and friendly.
Ross, Ryan: A pilot for the AIJ, Jay's and Cam's squad leader. Self-serious, but a huge nerd. Has a young daughter.
Sails, Jennifer: A pilot for the AIJ, former commander of the Esther Strova's mecha contingent, and squad leader to Kitty and Jay. A calm and respected commander. Was killed by Divine Navy Ensign Tanaka Mari.
Schmidt, Josef: Scans officer.
Shen Zhìháo: A pilot for the AIJ, former squad leader to Cam and Ryan, former mentor to Kitty. A stern and weathered veteran. Was killed by Divine Navy Ensign Tanaka Mari.
Tham, Jay: aka "J21". A pilot for the AIJ, Kana's lover, and a surviving J-Subject. Stoic and patient, with a temper that occasionally flares. Loves his surrogate siblings.
Wehrschmidt, Kitty: A pilot for the AIJ, Kana and Azara's squad leader. Grew up in the Jovian independence movement, serious and self-assured.
Yorke, August: The chief mechanic for the Esther Strova. Talented, but high-strung. Hates Kana.
The United Solar Empire
The North Family
Bal-North, Faiza: Born Faiza Bal, adoptive daughter to Nalah, adoptive sister to Mosi and Amani. A girl in her young teens and a mechanical prodigy, currently in the Imperial Academy on Titan.
North, Amani: An SRI lieutenant. Daughter to Nalah, sister to Mosi and Faiza, fiancée to Gloriana. An expert with scans systems as well as various forms of code. Unflappably cool and professional. The protagonist of Petals of Titanium.
North, Amir: Late husband to Nalah, father of Mosi and Amani. An accountant killed on Mars by the HSE as part of the Utopia Purges for his refusal to disavow his wife.
North, Mosi: A guard-lieutenant and mecha pilot in the Imperial Guard. Daughter to Nalah, sister to Amani and Faiza. A deserter from the Divine Navy, serving in exchange for a pardon.
North, Dame Nalah: A captain and mecha pilot in the Imperial Navy, wife to Amir, mother to Mosi, Amani, and Faiza. A famous war hero for her part in the Imperial Civil War. Was injured badly during the Saturn Invasion.
Perbeck, Countess Gloriana: A captain and mecha pilot in the Imperial Navy, fiancée to Amani. Bears the title of Countess Perbeck, although her family lands are still on Mars, in HSE hands, currently ruled by her cousin. A coldly serious woman, but an intense warrior.
Special Reconnaissance & Intelligence
Frost: An SRI technician reporting to Amani north. Was killed by pirates.
Jens: An SRI technician reporting to Amani North. Was killed by pirates.
Mendez, Amelia: An SRI commander and captain of the HIMS Creeping Ivy.
North, Amani: See above entry.
Owusu, Milo: An SRI commander and mecha pilot. Special liaison to the AIJ.
The Imperial Guard (USE)
Helios, Princess Daystar: Lady-High-Commander of the Imperial Guard. Niece of the empress, her preferred heir for the USE's throne.
J6: Formerly personal bodyguard to Princess Daystar. Died during the events of Petals of Titanium.
Li, Anton: A guardsman second-class and scans officer aboard the HIMG Goldray. Native-born Saturnian. Brother of Anja Li.
North, Mosi: See above entry.
Song Ji-ho: Captain of the HIMG Goldray. A member of House Song, his aunt is the holder of an Imperial Elector seat.
Vasquez, Lucinda: A guard-lieutenant and first officer onboard the HIMG Goldray. Devious. A native-born Saturnian.
The Imperial Navy (USE)
Andre, Lilian: Former captain of the HIMS Titanium Rose, former commanding officer of Amani north. Died during the events of Petals of Titanium.
Li, Anja: A sub-lieutenant and communications officer onboard the HIMS Nightshade. Friend and former shipmate of Amani North.
North, Dame Nalah: See above entry.
Perbeck, Countess Gloriana: See above entry.
The Imperial Royal Family (USE)
Helios, Prince Corona: The empress's son, in disfavour. Daystar's political rival. i named this character back in 2018 leave me alone
Helios, Princess Daystar: See above entry.
Helios, Empress Solana I: Empress of the USE, defacto direct ruler of Saturn.
The Holy Solar Empire
House Grangier
Grangier, Arianne: The youngest daughter of House Grangier's main family. A disappointment and a party girl. Secretly, a spy for the Jovian independence movement. In a quasi-secret relationship with her bodyguard, Agnieszka.
Grangier, Duchess Lorelei: The HSE-appointed governor of Jupiter. A former Imperial Elector who betrayed the USE during the Civil War. Mother of the year.
Grangier, Duke-Consort Renaud: An admiral in the Divine Navy, formerly in command of the HSE's Jovian Garrison. Helped command the Saturn Invasion, the Battle of Titan, surrendered during the events of Petals of Titanium, remaining a prisoner of the USE.
Leszczyńska, Dame Agnieszka: aka J32. A Knight of the Order Lunar, Arianne's bodyguard, and a surviving J-subject. Dangerously unstable, loves Arianne and what family she has.
The Divine Navy of Correction
Adler, Alvin: A young man recruited into the crew of the HDMS Sunspot. Friend of Tanaka Mari.
Dvorska, Baroness-Consort Allison: Admiral in command of the Divine Navy's Jovian Garrison.
Grangier, Duke-Consort Renaud: See above entry.
Green, Elias: A commander and mecha pilot in the Divine Navy. Formerly Mosi North's commanding officer and mentor.
Kron, Edith: A commander in the Divine Navy and captain of the HDMS Sunspot.
Quan, Ava: A young woman recruited into the crew of the HDMS Sunspot. Friend of Tanaka Mari.
Reider, Baroness Tabitha: A commander in the Divine Navy, captain of the HDMS Iron Tulip.
Salmus, Sir Ethan: A commander and mecha pilot in the Divine Navy. The original test pilot for the QDIMX Carbon Steel.
Smith, Andrew: A lieutenant and mecha pilot in the Divine Navy. Former subordinate of Mosi North, current subordinate of Elias Green.
Stone: A commander in the Divine Navy and captain of the HDMS Copper Blossom. Was killed in combat with the Esther Strova and its allies. Colleague of Tabitha Reider.
Su Limin: A lieutenant and mecha pilot in the Divine Navy. Former HSE Imperial Academy classmate of Mosi North, participated in the abusive hazing she suffered.
Tanaka Mari: A cadet and pilot in the Divine Navy, a young civilian recruited into the crew of the HDMS Sunspot. Pilot of the QDIMX Carbon Steel.
Yildiz, Sevda: A young woman recruited into the crew of the HDMS Sunspot. Friend of Tanaka Mari.
The Imperial Royal Family (HSE)
Helios, Emperor Dawnlight III: Divine Emperor of the HSE.
Helios, Prince Apollo: Son of the Divine Emperor, heir apparent to the throne of the HSE.
Others:
The J-Project
J3: A promising subject, died relatively early in the project due to a freak neural-interface testing accident.
J6: See above entry.
J21: See Tham, Jay.
J32: See Leszczyńska, Dame Agnieszka.
Dr. Parker: The head researcher for the J-Project.
Pirates
Beryl, Naiya: A mecha pilot with Ohara's Wolves. Former Divine Navy. Survived the Saturn Invasion and the Battle of Iapetus.
Ohara, James: Commander of the Ohara's Wolves and mecha pilot. Former shipmate of Himegami Kana. Killed in combat by Milo Owusu.