Third season of .

Two martial artists are brutally killed by a team of assassins, leaving their wards, a young boy and girl, defenseless. A martial arts master dispatches of the assassins, sparing their lives, and decides to take them in. He raises them and teaches them martial arts.

Taking place after the events of Heaven and Earth and before Exodius, Behind the Line depicts the moments of boys and girls after Soushi Minashiro returned home.