Rooster Fighter manga volume 7 features story and art by Shu Sakuratani.

While Elizabeth attempts to rescue their father, Keiji and Keisuke rejoin the battle with Hikari, the devil bent on destroying the two rooster brothers. Hikari has transformed into the ultimate expression of his evil power and it appears nothing can stop him. Keiji's not giving up, but this is exactly what Hikari's sinister mother wants—to force Keiji into a corner and push him past his limits to trigger his Righteous Egg. Keiji fights for justice, but is there a dark side to his new awakening?