In the year 2046, the human race faces destruction at the hands of enigmatic extraterrestrial beings. Mikako, deeply in love with someone, abandons her beloved to join an intergalactic campaign as a pilot. As she puts her life on the line to save humanity, Noboru waits anxiously for news of her fate. He languishes for days, then months, and ultimately, years, for every tidbit of information that might indicate if Mikako still lives. The unchanging vastness of outer space barely ages Mikako, while Noboru grows older with each passing moment. Despite the growing fissure that separates them, the two lovers struggle to sustain their bond in the face of daunting odds.