[Gintama/GinTaka/Brief GinTaka] Strike

Two agents codenamed White Yaksha and Shura are ordered to kill the Night King. Gintoki is on the verge of death, and Takasugi is badly wounded. Kamui becomes fascinated with Gintoki for killing the Night King with his own hands, and saves him for reasons of his own. Unhappy with the bond between them, Kamui tries to alter Takasugi's memories and make the two of them enemies. But he fails :3

After that comes the two men's revenge story (maybe), with the Shinsengumi showing up along the way. It's not a particularly heavy story.