It's September 1992. Tokyo was under attack by an organization called Kyomu. This was the beginning of what would later be called the "Tokyo Lost Life Phenomenon."

Oribe Midori who works as a teacher at a daycare center, along with the children, was trying to evacuate from the destroyed city of Tokyo. However, they got caught in the attack, and she became unconscious. When she woke up, the children were gone. In order to search for them, Midori climbed into the upper seat of Nana-2, a Jinki that was displayed at a nearby museum, but it won't move as she expected.

"Ah... the lower seat...!"

"You're right. This one is old. It won't move just from up there."

Then Ogawara Ryouhei appeared. He climbed into the lower seat of Nana-2 and activated it. Midori thought with this she could finally search for the children, but they were immediately attacked by Kyomu's Jinki, Vargoyle, and had no choice but to be drawn into the battle.

"If there's something you want to protect... protect them with your strength!!"

Though confused by the situation she finds herself in, Ryouhei's words make up her mind and decides to throw herself into the battle to reclaim Tokyo...

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