As New Year’s Eve draws closer, preparations for a holiday party are underway in Petersburg. In anticipation of the event, Eila Ilmatar Juutilainen of the 501st Joint Fighter Wing is determined to take Sanya V. Litvyak on a leisurely walk around the city. However, despite Eila's best intentions, she gets interrupted every time she gets a chance to ask Sanya out, ruining the moment and separating the girls. To make things worse, a Neuroi is approaching the base, threatening both the squadmates and the celebration in Petersburg.

The war between the Terrans and the Vers Empire of Mars has ended, allowing humanity to blissfully enjoy their lives in a time of peace. Nineteen months later, however, the Vers princess makes a shocking public declaration: "the Terrans are a foolish race that covets resources, destroys nature, and are devoted to the pursuit of pleasure." And so, to protect their precious Earth, she calls upon her knights to take up arms, and the raging battle between the two civilizations reignites. Slaine Troyard has found a place among the Martians, giving Earth a short respite from the war against the Vers Empire. However, a peaceful resolution seems inconceivable. The various people who fought desperately for survival in the past now find themselves in the midst of yet another bloody and chaotic conflict, one that will forever alter the fate of humankind.

A recap episode of the original series made to connect Yuuki Yuuna wa Yuusha de Aru: Washio Sumi no Shou to the sequel series Yuuki Yuuna wa Yuusha de Aru: Yuusha no Shou.

Second season of A Day Before Us.