I'm Miku Kohinata. The Symphogears have disappeared but a strange silvery stone, similar to a Relic, has appeared on the flesh, on the upper chest of all former Relic holders. I've got one.
After we discovered that these stones are connected to the Sephirah, beings living in another world, in a mysterious Library, my friends and I magically found ourselves in the same Library.
There, a mysterious woman, Angela, tried to kill us because we "hadn't been invited," but she was incapable of attacking us. Something prevented her from doing so. Our connection to the Sephirah, the Patron Librarians. We met them all later.
Although there are nine Sephirah/Patron Librarians in all (Roland doesn't count!), we are seven former Relic holders. Hibiki, Tsubasa, Chris, Shirabe, Kirika, Maria and me. But if we count the departed Kanade and Serena, that makes nine.
Each silvery stone is associated/linked with a Patron Librarian. Tsubasa is with Yesod. Unlike us, who are struggling to use the power of this new kind of Relic, Tsubasa and Yesod are in "Symphony". This means that she can transform into her Symphogear-like combat armor with no problem. When transformed, Tsubasa "becomes" Yesod, for the transformation is a fusion.
We thought we had nothing to worry about, apart from finding a way back to Earth, but then the Noises started attacking the Library and often. Fortunately, Tsubasa is always ready for battle.
However...
"Yesod?" She asks, while looking for him on the technological science floor. "Where are you? We're under attack!"
"Are you looking for the boss?" One of his employees asks. "He's in his office."
"Seriously? But I just checked!"
Tsubasa, frustrated, runs back to Yesod's office when he arrives.
"How many times do I have to tell you? We don't run in the..."
"This is no time to tell me about your rules, Yesod! Noises are attacking us!"
"Again? We eliminated some only 24 hours ago."
"I know, but..."
She hears Yesod sigh. He hates to be disturbed in the middle of his work. She knows it, but fighting the Noises is a priority.
Yesod holds out his hands to Tsubasa. Tsubasa, blushing, takes them.
"Let's do this." Say Yesod.
He starts dancing with her. It helps for the transformation.
"Are you going to begin or should I...?" Tsubasa asks before being interrupted by Yesod's melodious voice.
"♫ Gabriel... ♫"
"♫ Yesod... ♫"
"♫ Kagami Zizzl. ♫" They finish at the same time.
An intense light blinds the technological science floor and Tsubasa is transformed. Yesod has disappeared.
Being chased by a Noise, I'm looking everywhere for Hibiki, when I hear a deep female voice calling me.
"Miku, over here!"
"TSUBUSA! I mean, Yesod!"
I move towards him... towards them and the Noise gets sliced up. Yesod-Tsubasa still use blades as weapons, but they also have Artificial Intelligence skills, such as projecting battle holograms and hacking (possessing) certain types of enemies.
Yesod-Tsubasa asks me if I'm all right.
"Are you wounded? I can..."
"No, Tsu... Yesod. I'm not hurt. There are Noises on the Library’s other floors! And I can't find Hibiki."
"I'll take care of them. You stay here."
"But...!"
"I'm sure Hibiki and the others are fine, but you have to stay on this floor. It's for your own safety."
I nod, albeit hesitantly. Yesod-Tsubasa leaves me. I wait, worried and, to distract myself, I sing part of Yesod-Tsubasa's Battle Song. The few words I managed to hear during a previous attack.
A moment later, I smile as I see Hibiki coming towards me. She tells me that Yesod-Tsubasa is still fighting Noises and that we're staying together. Happy, I throw myself into her arms. Hibiki. I love her and she loves me too. I get the impression that Tsubasa is falling in love with Yesod, although she keeps telling me otherwise.
"We're Symphony Partners, that's all!" Tsubusa always tells me.