The Faults of a Young Sensei

Houtaro transforms into Iron Gotchard, but his physical strength is depleted and the transformation is canceled. He is saved by Fuga, the father of Rinne, who suddenly appears and escapes from the battle with Dread Type One.

Fuga explains about "an incident" that occurred 10 years ago, which is the reason why Minato abandoned Houtaro and the others to follow Geryon. Houtaro and the others, who understand Minato's true intentions, confront him once again...!