South Star Waterfowl Fist! The Beginning of a Tragedy of Men Too Strong!!

Rei arrives at Mamiya's village and rescues Rin. He confronts the leader of Ken-oh's Invasion Division, who tries to use Airi as a distraction. But Airi, spurred on by Rin's courage, gains the strength to fight for herself again. Rei goes on to defeat the Division leader, only to come face to face with none other than Ken-oh himself.