In Edo, Sakata Gintoki runs a “Yorozuya” and unexpectedly meets an orphan named Seita, who lives as a pickpocket. Upon learning that Seita is searching for his long-lost mother, who may be the courtesan Hinowa of the enormous underground city Yoshiwara, which operates above the law.

The courtesans in Yoshiwara are controlled by the Night King, Hosen, who takes pride in his overwhelming power among the warrior race of the Yato and possesses immense wealth and authority, completely dominating Yoshiwara. To fulfill the boy's wish, Gintoki and his companions decide to take action. Will their connection be able to illuminate the vast darkness?