During a film premiere, Gintoki arrests a supposed movie thief. After reviewing the security footage, he is whisked away to a desolate, post‑war rendition of Edo where an enigmatic outbreak dubbed the "White Plague" has decimated humanity. It becomes clear that the alleged thief was actually an android time device, and Gintoki has been propelled five years into the future! Shinpachi and Kagura, his former Yorozuya allies, have split apart and now operate as hardened lone warriors, while Gintoki has vanished for years, leaving only a cryptic note in his diary.
Equipped with the disguise supplied by the time machine, Gintoki clumsily gathers the Yorozuya group to probe the White Plague. He soon learns that rescuing tomorrow hinges on confronting shadows from his own past. With resolve to face a formidable adversary, he discovers that with a ragged crew of companions and supporters beside him, he need not fight solo. Their combined experience and bond give them hope against the looming threat, proving that unity can overcome even the darkest despair.