After the U-17 camp ended, the group of young students came to the world of Gintama due to a "mysterious driver" on their way back to school and were scattered in different places. Later, they got back together with the help of Wanshiwuwu. Just as everyone was preparing to help Seigaku return to their world, Sougo accidentally learned during a battle that there was a conspiracy behind Seigaku's return. Echizen and Sakuraba Rie met in a fight. When the two were chatting, Rie learned that Echizen was now living in the Master House, and she also joined the Master House with relevant information and secret reports: The demon clan led by Yukimura Chizuru wanted to destroy the world in order to change the appearance of the world they lived in, so that the Shinsengumi could escape the fate of a tragic ending. Of course, Chizuru just wants to change the Shinsengumi, but someone else has the real ambition. After learning of this news, Wanshiwu joined forces with the Shinsengumi, Momoka, the anti-Yi patriots, Kabukicho, and Seigaku to destroy the plan, protect what they cherish, and stick to their beliefs!