Summer of 1989. Pioneers' Camp "Sovyonok".
For Semyon Persunov, the son of Soviet diplomats, a "privileged kid" burdened with a fatal illness, this camp session will be unlike any other.

For the first time in years of struggling with the mysterious "PSR Syndrome", his mind is finally free from foreign intrusions. And it is during this one precious week that he meets the one who will change everything - the Japanese singer Hatsune Miku, who becomes his last hope… and his future.

In just seven days of freedom, Semyon manages to save Slavia’s puppy, help Miku come to terms with her future, and convince Ulyana not to follow in his tragic footsteps.
But as the camp draws to a close, a sense of incompleteness begins to grow inside him.

And then, one evening, he hears from the Japanese girl the words he feared most…