After Splinter kills Shredder in issue #50, Karai offers him her sword and the role of jonin (leader) of the Foot. He accepts and gives Karai permission to travel to Japan with select soldiers to study history in order to attain honor for the Foot. She gets involved in a turf war between two Yakuza clans and is nudged by one of their leaders into embarking on a quest to recover the "Kira no Ken", an ancient sword imbued with mystical powers. When she learns that she was betrayed by him, Karai ends up taking over the entire Tokyo underworld. Under the baleful influence of the sword, she starts a vicious turf war with Splinter and the original Foot Clan, critically stabbing Splinter's faithful lieutenant Jennika when she refuses to switch sides.