Gin-san's invited to a Joi Rebels reunion, where he finds Katsura and Sakomoto, fellow survivors of the Joi War era, reminiscing about the past. Sick of seeing them in OPs and EDs all the time, Gin-san tries to leave immediately, but he's shocked by the revelation that the organizer of the reunion wasn't Katsura or Sakomoto, but rather the phantom fifth man, Kurokono Tasuke.
Using flashback arcs to give Jump anime 
second winds is almost standard procedure.
استغلال آركات استرجاع الأحداث لإعطاء أنيميات
جامب دفعة جديدة إجراءٌ أساسي تقريبًا
Es común darles un segundo aliento a las 
series de la Jump con una saga de flashback.
Usar histórias em flashback para dar vida
 nova aos animes da Jump é o padrão.