In an alternate history of the aftermath of World War II, Japan has been cleaved in half, with the south&mdash;Honshu and the other islands&mdash;allied with the United States and the northern island Hokkaido annexed by the enigmatic Union. It was on Hokkaido that a mysterious tower had been built, a strand of metal reaching up out of the atmosphere, visible from the northern tip of Honshu. In 1996, three teenagers, Hiroki, Takuya and Sayuri, make a pact&mdash;they will build an experimental aircraft, almost invisible to surveillance, cross over to Hokkaido and unlock the secrets of the tower. Their dream was never realized, because Sayuri was sent to Tokyo for treatment after she fell into a coma. It is now three years later. The rosy illusions of youth have fallen away, but not the unbreakable strength of the trio&rsquo;s promise. The truth of the tower will be uncovered, and with it, the link between it and Sayuri&rsquo;s mysterious, carefully tended condition.

In an alternate timeline, Japan was divided after losing World War II: Hokkaido was annexed by "Union" while Honshu and other southern islands were under US sovereignty. A gigantic yet mysterious tower was constructed at Hokkaido and could be seen clearly from Aomori (the northernmost prefecture of Honshu) across Tsugaru Strait. In the summer of 1996, three 9th-graders had made a promise that one day they'll build an aircraft and unravel the tower's mystery, but their project was abandoned after the girl, Sayuri Sawatari, began experiencing sleeping sickness and transferred to Tokyo for better treatment. Three years later, Hiroki Fujisawa accidentally found out that Sayuri had been in a coma since then, and he asked Takuya Shirakawa to help him finding a way to revive her. What they don't know yet is that Sayuri's unconsciousness is somehow linked with secrets of the tower and the world.
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(Source: Anime News Network)

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