Fate is a 19-year-old commissioned officer of the TSAB. She lives on Earth in Uminari City with Lindy, who has retired from her position as Admiral, having had too much excitement and seeking a desk job. Fate goes to school with Nanoha, Hayate, Suzuka, and Alisa. Though early promotional material suggested that she would abandon her battle uniform for a TSAB suit, a recent update of the nanoha.com website showed her in her Barrier Jacket, which appears to have grown to continue to fit her. She also seems to have gained a white cape, according to two promotional pictures; what the cape is for is unknown. In the manga, both the TSAB uniform and the Barrier Jacket are used with the Barrier Jacket overlaying or replacing the uniform when activated for combat situations.

She is the head of the Lightning Squad, and an S+ mage without limiters, an AA mage with. Showing great concern for her squad, particularly Erio (she is his guardian) and Caro, a child that she took in when no one else would, Fate takes her position as leader very seriously.

Hayate Yagami (八神 はやて, Yagami Hayate?)
Four years after the A's epilogue, Hayate has indeed dedicated herself to her job to the point of dropping out of Earth schooling, and has surpassed even Nanoha and Fate in ranking. She and the Wolkenritter now only work together on special occasions, save for her constant partner, Reinforce II

Vivio Takamachi (高町 ヴィヴィオ, Vivio Takamachi?)
A mysterious child whom was found with a relic, Nanoha has taken in Vivio. Vivio has complete heterochromia, her left eye being red while her right being green. She is a man-made mage. She is named for the Subaru Vivio.

Four years after the A's epilogue, Second Lieutenant Vita is sub-commander of the Stars Squad in the TSAB, working directly under Nanoha, who, in turn, obeys Hayate. She and the other Wolkenritter were kept close to Hayate and each other-- Shamal and Zafira are support, Signum is with the Lightning Squad-- because they work most effectively as a team. In this season, Vita shows that she is still hurt emotionally from the times she couldn't be there for Hayate and Nanoha, and will go to extreme levels to protect them. As portrayed in episode 25, (after being stabbed through the back) broke her device, Graf Eisen, while desperately trying to destroy the engine for the "Cradle" ship controlled by Scaglietti and his combat cyborgs.

Ten years after the epilogue of A's, Signum became the sub-commander of the Lightning Squad of the TSAB, working under Fate, who worked under Hayate. Unlike Vita, however, she did not participate in training the trainees, under the pretense that she is an old fashioned knight and can only teach to them is to get close to their enemies and rip them apart. However, near the end half of the series, she accepted the request of Erio Mondial to spar with him.

During the attack of Saint's Cradle, Signum fought off with Knight Zest Grangeitz, who united with Agito. She performed unison with Reinforce Zwei, but only managed to end the fight with a draw. The fight continues inside the headquarters of Capital City Defense Forces, and Signum came out victorious. In his dying breath, Zest asks her to take care of Agito and Lutecia Alpino.

Teana's parents passed away when she was at a very young age, so her older brother, and only sibling, took care of her afterwards. Unfortunately, when Teana became ten in age, her brother was involved with a crime case that had cold-hearted superiors leading said case. Injuring but failing to capture the wanted mage, he was ridiculed by aforementioned superiors of being 'useless and a failure' because he is 'supposed to risk his life, even sacrifice it, to make the mission a success'. Having a brother that was shamed from his final mission to his death, Teana made a goal to prove it to everyone that the bullets of the Lansters are not to be taken lightly. Because of this, her dream is to be an enforcer, just like her brother. She is the partner and best friend of Subaru, but because of her tsundere personality, strongly denies it at times.

At the end of the series, Teana seem to work as enforcer under Fate at Time-Space Administration Bureau.

Reinforce II is a smaller version of Reinforce that has been accepted as a member of Hayate's task force in the Time-Space Administration Bureau; she even wears the uniform. She can be summoned as a hologram from the Schwertkreuz, and promotional pictures for StrikerS show a very solid Reinforce II accompanying Hayate as well.

Reinforce II (pronouced "Zwei") is apparently solid, and needs to eat and sleep daily; she has a "room" of sorts in Hayate's bag. She holds the rank of Sergeant Major and serves as Hayate's SNCO/ Chief of Staff in Lost Property Management Division 6.

In the anime, she is shown capable to unifying with other Wolkenritter members (Vita and Signum) to boost them in battle, although because of their incompatibility, their union is not as good as Hayate's. When unifying with them, their clothes change its color to white.

When not in Unison Mode with Hayate or the other Wolkenritter, Reinforce II uses a blue book called the Book of the Azure Sky (蒼天の書, Sōten no sho?) and appears to specialize in ice-based magic

Four years before the events of the series, Subaru had been caught in a fire at a Mid-Childan airport along with her older sister Ginga. Confused and crying, just as a statue was about to crush her, she was rescued by Nanoha. Nanoha created a hole in the roof using Divine Buster to make her exit with Subaru, and the experience left Subaru with a deep admiration for and the desire to be just like Nanoha.[2]

At the very start of the series, Subaru participated in a test with Teana Lanster to raise their Mage Ranks from C to B, though she didn't know that she and Teana were being observed by Nanoha, Fate T. Harlaown and Hayate Yagami as potential students and members of a new division of the TSAB Ground Armed Forces, Mobile Division 6. Though the 2 were accepted into the new division, they had failed the test. But they were given a special opportunity to retake it without having to wait. [2]

Subaru's excitement at being a member of the same squad as and being taught directly her idol may have had her jumping, but Subaru, having a completely different way of fighting from her commander, instead trains in close combat with her sub-commander, Vita. Subaru's style is unrefined, as she initially opted to use barriers in situations where shields are more appropriate.

At an undetermined time before, but at least four years prior to StrikerS, Erio was taken away from his parents house. During the incident, he learned that he was an artificial human being created as a product of the Project F. Broken in spirit by the revelation and by being relinquished by the couple that he had known as parents once they learned that the truth had been discovered, Erio was at the mercy of his captors. In a strike of luck however, he was found and protected by Fate Testarossa, who decided to take care of him shortly after[2]. Even though he was a legal member of the Harlaown family (since he had Fate as his guardian and Lindy Harlaown as his adoptive parent[3]), Erio was placed under a special protection program by the Time-Space Administration Bureau and made to live at the TSAB's headquarters until he was 8 years-old[4].

Erio eventually learned magic and joined the Time-Space Administration Bureau's forces and, by the time when the events told in StrikerS began, he was a young Private 2nd Class ranked "B" as a mage. Once transferred to the Mobile Division 6, Erio was placed under the command of his former guardian in the Lightning Squad and code-named "Lightning 3". It has been hinted that he and his squad-partner, Caro, are developing a romantic relationship.

At the end of the series, Erio asks to tranfer to TSAB-administrated world No. 61 and works with Caro at a wildlife preservation.

Native of the TSAB-administrated world No. 6, Alzas, Caro was born under the nomad-like "Minority Tribe" known as Lu-Lushe Since very little, she was taught the trible's traditional summoning arts: the "Dragon Summon". Caro exhibited a rare talent to the craft, to the point that she could already summon two powerful dragons by the age of six. This frightened the elders of her tribe however, who believed that her power would attract misfortune, and lead them to banish the girl[3].

Sent to stay at a TSAB's HQ-attached special protection facility, Caro had a life of many restrictions and few liberties[4] imposed upon her. This would went on forever, had she not met with Fate T. Harlaown one day by pure chance[5]. After hearing about Caro's past, Fate decided to take her in and become the girl's guardian. Similarly on how it was with Erio Mondial, the circumstances prevented Fate and Caro from living together from the beginning. Instead, the girl started to live and work at a wildlife preservation area in the TSAB-administrated world No. 61, Supools, where she discovered that her talent as a summoner also helped her to deal with all sorts of animals. Caro remained there until the day that she was invited to be part of the Mobile Division 6.

Although talented, Caro still has much to mature as a mage. At the beginning of StrikerS, she was "C+" ranked, ground-based summoner that had little to no control over the dragons that she invoked. Caro eventually overcame this flaw after her ingression in the Division 6 and, after being assigned to the Lightning Squad under the sign-name of "Lightning 4", soon became a reliable member of the Forward Team. She seems to harbor romantic feelings towards Erio.