After a year away, Shinpachi Shimura returns to Edo only to be shocked by the drastic changes that have transformed his Yorozuya colleagues, Gintoki and Kagura, into entirely different individuals. And it's not just them – everyone in Edo has undergone extreme changes in appearance and attitude, leaving Shinpachi bewildered. His shock is further compounded when he learns that his sister Otae is pregnant with her husband, Isao Kondou's, child – a man who happens to be a notorious stalker and a high-ranking member of the Shinsengumi. At their request, Shinpachi joins the organization, only to find even more surprising transformations. Despite the chaos, Shinpachi finds comfort in Vice Chief Toushirou Hijikata's consistent demeanor. Together, Shinpachi and his unlikely ally from the Shinsengumi set out to restore Edo to its former glory. Of course, with Gintama's trademark humor, parody, and allusions, the Yorozuya crew must navigate through a weird and wacky world filled with extraterrestrial creatures.