May 1, 1945- Germany.On the eve of Berlin's collapse, a group of men and women carried out a certain ritual. To them, suffering defeat in the war meant nothing. If anything, the countless lives lost in the battle served as a catalyst to their sacrificial ceremony. Whether or not their attempt bore fruit ― not a soul knows. Following the war, they faded from sight, mind, and eventually into the realm of myth. ・・・・・・・・・・・・ 61 years later ― Japan, 2006. Ren Fujii, a young man attending high school in Suwahara City, finds his friendship with his old buddy Shirou Yusa shatter to pieces following a certain incident, ending in a vicious fight that sees Ren hospitalized for two months. The season shifts from autumn to winter ― to the dawning weeks of December, with Christmas on the horizon. Having lost his best friend, Ren leaves the hospital with the intention to rebuild his new life without Shirou.