Karai, is a character from the 2003 Teenage Mutant Ninja Turtles show. Like other versions of the character, she is the Shredder's disciple, adopted daughter and a high-ranking member of the Foot Clan. She is a woman torn between honor and family, she appears both as an ally and enemy to the Turtles, a dichotomy that plays a part in most of her appearances. Her allegiance varied throughout the series: first being an anti-hero (or anti-villain) during seasons 2-3, then villain in seasons 4 and 5 and finally became heroic near the end of season 5 and in later episodes.
As a child, Karai was found and adopted by evil alien Ch'rell after her parents abandoned her at a young age. He took her in and raised her as his own, teaching her ninjutsu. An aspiring practitioner of Bushido, she became his most trusted follower, even trusted to his true identity as Ch'rell and told her that the Utroms were savagely hunting him (and in his mind they were). When the Utroms fled for New York, Karai remained in charge of the Japanese Foot Clan. Karai first appears as one of the highest-ranking members of the Foot Clan, similar in status to Hun (who holds a grudge against her); eventually, she becomes the clan's leader.
When the Purple Dragons, the Mafia, and the Foot were fighting for control of New York City after the Shredder's reported demise, Karai arrived in the city after hearing the news of the gang war taking place and quickly enlisted the aid of the Turtles to stop it, promising an end to the Foot’s vendetta against them in exchange for their assistance. Leonardo, believing that Karai was honorable despite her legacy, convinced Donatello and Michelangelo to aid her. Raphael initially refused, although he later recanted. Together, Karai and the Turtles eventually retook control of the New York Foot and consequently its underworld. However, the end of the story, it was revealed that Karai had been manipulating the Turtles (much to her dismay), and had been working with the not-dead Shredder all along. However, she showed sadness when the Ch'rell vowed to get revenge on the Turtles after she had made a truce with them.
Karai and the Foot reappeared in Rogue in the House, Part 1, where a fully-healed Ch'rell retook control of the Foot. As his first order of business, he deployed a killer robot (disguised as Splinter) to eliminate the turtles. Realizing that their agreement with the Foot had been recanted, the turtles decided to face the Foot again in their temporary HQ—a ship stationed at the docks. Leonardo, Raphael, and Splinter were taken hostage during their encounter, and Karai was forced to fight Leonardo. Despite Leonardo's lack of resistance, she proved unwilling to kill him.
Karai's internal conflict – her loyalty to the Turtles as fellow Bushido-practitioners vs. her loyalty to Ch'rell – was the main thrust of her Season 3 storyline, as she was pulled from both directions to take a side during their various encounters, even working together with the Turtles at times. She also appears in a cameo in Japan. Karai managed to stay in the graces of both sides until the Turtles faced the Shredder again in the season's finale. As the Turtles were chasing Ch'rell, Karai tried to reason with Leonardo, pleading him to let her father leave. When Leonardo refused to let Shredder go, Karai fought alongside with Ch'rell and (unintentionally) accidentally stabbed Leonardo in the shoulder with his own sword, damaging his carapace, although she later prevented the Ch'rell from killing the Turtles while they were unconscious. Despite her efforts, however, in the end, the Shredder was taken prisoner and exiled by the Utroms, while Karai and the young Foot Tech Division Head Dr. Chaplin are also captured and sent back to Earth and placed in a prison. Before disappearing with Dr. Chaplin, Karai cried out to Leonardo: "This is not what I wanted!".
In the fourth season, Karai is one of the two main antagonists (alongside Agent Bishop).
With Ch'rell gone and dead in the eyes of the world, Karai took over the Foot as well as the mantle of the Shredder (in a deleted scene she even says that Karai "no longer exists", completely replaced by The Shredder) sometime after she and Dr. Chaplin got out of prison. This new Shredder "would retain the traditional iconic elements, but have a different treatment". Furious at what she saw as a betrayal by the Turtles, Karai plotted her revenge against them, first attacking them on the psychic plane via Foot Mystics, and later coordinating and leading an assault against them at their lair, which she believed successful. She later once again duels Leonardo (who was not at the lair at the time of the assault), who defeated her but then departed with the warning to leave his family alone and giving her one last chance for redemption.
Unknown to the Turtles or Agent Bishop who initially charged them with retrieving the artifact, the Heart of Tengu was a mystical artifact that allowed the Foot to control its Elemental Mystics, who were in reality the heralds for a man-demon that had centuries ago terrorized Japan as The Shredder. The destruction of the clammer unleashed a chain of events that resulted in the demon Shredder’s resurrection. His first target was Karai, who had "usurped" the Shredder's name. The Tengu Shredder and his heralds made their way to Foot HQ. Karai had the Foot prepared for this, having developed mystic-based technology to combat the supernatural, but despite her efforts and those of the Turtles, who believed her the key to stopping him, the Shredder bested Karai in battle, seriously injuring her. Karai was rescued by the Turtles and taken back to April O'Neil's apartment, where she was tended to. Dr. Chaplin followed her trail, and was brought to her after being caught snooping around the building. Karai heals and, recognizing the threat the demon Shredder posed and her inability to stop it by herself, Karai agreed to a "temporary" alliance with her enemies. It was soon learned that because she shared The Shredder's mantle, Karai had the latent psychic ability to lower Shredder's defenses through a shared link. This was accomplished by absorbing the majority of the Demon Shredder's power into herself, a power that she presumably keeps. This gave the Turtles an advantage in their final conflict with the demon. Karai helped pave the way for her namesake's destruction, and Dr. Chaplin helped the Turtles co-ordinate their battles against the demon. After the battle, Karai, touched by Chaplin's devotion to her, promised him that she was going to worry more about the immediate future, and they departed the battlefield hand-in-hand. It is possible that after it she forgot her grudge against the Turtles and resolved their difficulties off-camera considering what happened in later episodes.
Back to the Sewers
Karai next appeared in the season finale, Wedding Bells and Bytes, having been invited to attend the wedding of April O'Neil and Casey Jones. It appeared as if she and the Turtles had resolved their difficulties off-camera, and she arrived at the ceremony with Doctor Chaplin by her side. She and Chaplin later assisted the Turtles in fending off the sudden onslaught of the Cyber Shredder and The Foot Clan. Though she had no lines, it was apparent that she had moved on with her life and was no longer involved with the Foot.
Karai also makes an appearance in the 2009 animated film Turtles Forever, in which Karai freed Ch'rell from the clutches of the 1988 Shredder, Krang, Bebop, and Rocksteady, and aided the Utrom Shredder in modifying the Technodrome with Utrom technology. The Utrom Shredder, consumed with rage for revenge on the Turtles, wanted to destroy every dimension where Ninja Turtles exists, even though such an action would most likely destroy himself. Karai began to have doubts about the whole affair and secretly intervened rescuing the classic Turtles, '88 Shredder, Krang, and 2003 Splinter as the Utrom Shredder was prepared to destroy both the 1988 and 2003 Turtles. In the end, at the Turtles Prime dimension, (Mirage Turtles) Karai fought alongside the Mirage, 1988, and 2003 Turtles as well as the 1988 Shredder and Krang and 2003 Splinter, to stop the Shredder from destroying Turtles Prime. In the end, after Ch'rell was defeated, she commented that the Shredder would always return.
A major plot arc that started with her character during Season 2 of the show was that she was loyal to her father, despite his dishonorable ways. After Ch'rell's exile at the end of Season 3, Karai spent all of Season 4 and Season 5 hating the Turtles and possibly after season 5 making a truce the with Turtles. When she appeared in 'Wedding Bells and Bytes' as a guest of April & Casey's wedding, it was assumed that her vendetta with the Turtles was over, but Turtles Forever (if it is meant to fully correspond with the 2003 series' plot line) indicates that with Ch'rell's return, her loyalty to him does not exceed her truce with the Turtles. But during Turtles Forever, she finally betrayed The Utrom Shredder and became a friend of Turtles once again.
- Karai is more confused of loyalty to the Shredder or about honor.