After the war, Japan was divided into north and south parts. American troops ruled Aomori prefecture in the west, and Hiroki Fujisawa and Shirakawa also liked their classmates Zadu Yuri in the same grade. They all have Sakuji in their hearts, and that thing-the Tsuyoshi Strait north of the border, the towering cloud "tower" established by the Hokkaido Alliance of Japan. The huge and mysterious tower was the yearning of three young girls who agreed to build a small plane and fly to the tower to find out. You Li transferred to Tokyo in the third year of high school. The two teenagers gave up their plan to build a plane. Haoji was admitted to Tokyo's high school, and Tuo continued to study at Aomori's high school, going farther and farther along each other's path. However, years later, Sayuri fell into a deep sleep in the hospital! The sudden illness brought the three together again. The illness of sleeping has a mysterious connection with the power of the tower, and the tower itself seems to have become a stronghold of war between the north and the south of Japan. The three people involved in war and love, in the end is to save the reason, or save the world! The answer to fate seems to be on the other side of the cloud, where they once agreed.