: The "piece" that connects them—their shared past and the tragic choice Gintoki made years ago to save his friends by executing their teacher.
: The climax of the long-awaited duel between Gintoki and Takasugi , intercut with emotional flashbacks to their childhood at Shoyo's school. Gintama' (2015) Episode 40
For (which is Episode 305 of the overall series), titled "Sworn Enemy," the most iconic "piece" or element is the intense, high-stakes battle between Gintoki Sakata and Shinsuke Takasugi . : The "piece" that connects them—their shared past