Crossing Swords! Roger and Whitebeard!

With Oden out on the water, Orochi fills in for him, only to draw the daimyos' distrust for belonging to the reviled Kurozumi line. His history is then revealed. Pursued as a child for crimes his grandfather had carried out, he fled into the woods and stumbled onto a run-down cabin where an elderly couple, Semimaru and Higurashi, were sheltering.

Higurashi explains the truth: unable to sire an heir, the Kouzuki shogun had left five houses contending for the line of succession, the Kurozumi and Shimotsuki among them along with the Uzuki, Amatsuki, and Fugetsu. Grasping for power, Orochi's grandfather murdered the rival daimyos, yet the shogun finally produced an heir in Sukiyaki. Once the plot was uncovered, the grandfather took his own life and the Kurozumi name sank into scorn. Convinced that Sukiyaki's birth had cost him the throne, Orochi accepts a Devil Fruit from Higurashi, who can mimic anyone, gaining a Zoan power that turns him into an eight-headed serpent. To fund weapons he robs Yasuie while masquerading as a servant and wrings loans from Oden that go unpaid, while Higurashi impersonates first Oden and then Sukiyaki, easing Orochi into the palace and at last faking the shogun's death. Overseas, in his fourth year aboard, Oden welcomes his daughter Hiyori, then picks a losing fight with Roger before Whitebeard arrives to trade blows.

The adaptation pulls the Kurozumi persecution forward, showing Orochi fleeing pursuers before he meets Higurashi and Semimaru, whereas the manga held that reveal back until Orochi told it to Oden far later. It also stages Orochi swallowing his serpent fruit and undergoing his first transformation with it.