With the letter from Takasugi proving to be a catalyst, the Joi rebel gang starts to remember Kurokono, and takes a trip down memory line to the Joi War era. After a gruelling battle with the Bakufu army, Gin-san and his comrades were taking a momentary rest at an abandoned temple.
That must be why Takasugi sent this.
لا بد أن تاكاسوغي أرسل هذا لذلك السبب
Eso debe explicar por qué 
Takasugi envió esta carta.
Por isso o Takasugi mandou isto.