Odd Jobs, Katsura, and Sakamoto disguise themselves as Renho to join Fumiko in infiltrating the enemy base.  Dark Vader, feared by all as the evil lord, plans to use the Renho's anti-samurai Gunsams to attack while the people of Earth are distracted by the rain.  Gintoki and the others must stop the invasion of Earth before it's too late, but instead they appear to be bonding with the Renho.  That is when Elizabeth, General Eren, appears!
When we first started Gintama, we 
figured there would never be any mecha.
pensamos que nunca sería un anime de Mechas.
achamos que nunca teríamos um mecha.