Ninja twin mechanical beasts appear

Synopsis

Dr. Hell gives a secret mission to the small Mechanical Beasts Brothas S1 and S2, trained in ninjutsu, and sends them to the lab. The moment Mazinger Z deploys, there's a brief instant when he's defenseless. The plan is to plant small cobalt bombs in that opening and blow him up. Meanwhile, a woman named Risa had abandoned her own baby at the lab's gate. Having lost everything and wandering alone in the mountains in search of a place to die, she learns that Brothas' bombs have been planted at the very lab where she left her child.