Youko Hazama is the mother of Shouko Hazama.  Later in the series she is chosen as the caretaker for Canon Memphis, eventually adopting Canon as her second daughter.

Years before the events of the anime, Youko was one of many of Tatsumiyajima's adults caught in the sterilization of Japan caused by the Seto Inland Sea Mir. In the ensuing chaos surrounding Japan, Youko was afflicted with extreme radiation sickness as a result of the many attacks on the country, resulting in harsh symptoms when not under the protection of Tatsumiya's own Mir.

After becoming a part of Japan's Arcadian Project and making a life on Tatsumiya, Youko was chosen as a suitable parent by the Albericht Organization, adopting her daughter Shouko in the process.

She works as a science teacher in the school when not working in the Alvis hangars.

(Source: Alvis)

Tatsumiyajima is the central island in the middle of a small cluster of islands, in a sleepy backwater of the Japanese isles. Not much happens there, and the island's young people go to school knowing that their lives are likely to remain peaceful and undisturbed. Or so they have been taught... but the truth is different. The fate of mankind is on the line, and Tatsumiyajima is the last line of defense against a hostile and incomprehensible enemy. At the center of it all, fighting for Humanity's continued existence, is the giant robot Fafner, the dragon that guards this final treasure of mankind.
 
(Source: Anime News Network)
 
Note: The last episode aired with a runtime of ~48 minutes as opposed to the standard 24 minute long episode. In the DVD release and subsequent home video releases of the series, the final episode was split into two separate ~24 minute long episodes.

Ex-member of the famous all female acting group in Japan the Takarazuka Revue (1987-1997).

2150 AD. The battle against the silicon-based Festums from outer space reaches a new phase. Fragments of the North Pole Mir were scattered throughout the world. Eventually, they began to act on their own as independent Mirs. Most hated humanity and attacked them, but some chose to coexist with mankind. Some with the same way of thinking existed within the human race, as well: those who were both human and Festum. They added to the chaos of the battle and brought about even more hatred.
 (Source: Crunchyroll) 
Sequel to Soukyuu no Fafner: Dead Aggressor, set two years after Heaven and Earth.

Second season of Soukyuu no Fafner: Exodus.

A hiveminded alien force reengages war with Tatsumiya Island years after Kazuki led a team of mech pilots to destroy them. In an explosive battle over the fate of humankind, the young warriors risk everything to save their only home from assimilation. (Source: Crunchyroll)

Yumi Ikoma and Ryou Masaoka are children who have been selected to take part in a top secret mission, to be the pilots of the first Fafner combat units; the last chance of survival for the human race. The enemy is ruthless, remorseless and is able to read the minds of humans. Therefore, the details of this mission are kept a secret even from the personnel involved. The young pilots must use all their courage and faith in order to survive and complete their mission or the fate of mankind would be compromised.
 
(Source: Anime News Network)

Episodes 10-12 of the Soukyuu no Fafner: Dead Aggressor - The Beyond series.

Episodes 4-6 of the Soukyuu no Fafner: Dead Aggressor - The Beyond series.

Announced at the Soushi Minashiro Birthday Fes 2021. Initially promised to fans during the 2017 birthday event, this self-contained entry to the Fafner series will be a "peaceful spinoff". 
(Source: Anime News Network, edited)

Episodes 7-9 of the Soukyuu no Fafner: Dead Aggressor - The Beyond series.

Tatsumiya Island is a small, idyllic haven for those lucky enough to call it home...until a surprise attack by a savage enemy shakes the water-locked paradise to its core. With Festum on the warpath, it's up to the island's dedicated inhabitants to pilot powerful Fafners and fight back! Before the gun smoke clears, illusions will be shattered and lifelong friendships will be stretched to their limits. Will this peaceful island survive the chaos of all-out war? Fafner- Dead Aggressor is a full-throttle fight in the name of defending peace and defeating evil! When a group of friends gears up to take on vicious Festum attackers, there's no telling who will become a hero...and who will be sacrificed to the ravages of battle. Life as they know it is on the line, and these brand-new soldiers learn to trust their instincts (and one another) in order to man their Fafners with fearless skill. Man and machine unite to take down all invaders...and save the homeland!
 
(Source: DMP)