The story of Heiwajima Shizuo being tricked by Orihara Izaya and then traveling through time
Shizuo went to the city where ghouls existed and met the little angel Kaneki.
The story of two people going through a series of things, traveling through different worlds, getting to know each other, and finally returning to Ikebukuro.
The timeline is when Kaneki first became a ghoul. After this world is almost the same, he then travels to other worlds.
CpKanekiken
Probably a slow travel story