Ashi and her six sisters were birthed from the High Priestess, the leader of an all-female cult of Aku, and raised as assassins by them to do what no other fighter could do: Kill Samurai Jack. The High Priestess named them the Daughters of Aku and raised them with the most brutal of training throughout all of their childhood and youth, attempting to sculpt them into the ultimate warriors. During her training as a child, Ashi found a hole in the wall to gaze upon the outside world. The High Priestess told her that the world was a creation of their master, Aku, and that it was under threat so long as Jack lived to oppose Aku's rule. She was then thrown back into training and received punishment. When their training was complete years later, they donned their masks and head coverings, and set out to fulfill their mission. (Episode XCII)
Ashi and her sisters set up traps for Jack in a forest, destroying his motorbike and starting an intense battle with the samurai, forcing him to hide and later escape to an abandoned temple. Ashi and her sisters looked for their hiding enemy, pursuing him to the temple's underground crypt. Here they had another intense battle with the samurai, but he succeeded in killing one of Ashi's sisters and blew up the temple with the others still inside. (Episode XCIII)
After breaking out of the rubble and tracking the samurai to a forest, Ashi fought Jack again in the next episode. However, this time Jack had the elements of concealment and surprise on his side, rather than the other way around as previously. Unlike their first battle, she found herself and her sisters overwhelmed as one by one Jack killed the other Daughters until only Ashi was left, hanging off a cliff by the chain of her kusarigama. Seeing her sisters perish and having been bested, Ashi had a momentary breakdown as she ranted and swore that she would kill Jack, even as he dropped her to her presumed death. (Episode XCIV)
Initially playing dead, Ashi survived the fall and tried to kill Jack again numerous times, despite being chained up with her own weapon, eaten whole by a giant monster and Jack's numerous attempts to save her life, undeterred from her purpose. Eventually, after escaping the monster, Ashi attempts to kill Jack with her sickle by sneaking up on him, before noticing a ladybug fly by. This triggered a flashback to when she was a small child and training with her sisters, when a ladybug flew into her hand and she observed the beauty of it, before it was unceremoniously squished and killed by her mother, labeling it a distraction and "not part of Aku's order." Ashi continued to hear these words until she sees Jack hold the ladybug in his hand and releasing it unharmed. After being saved by Jack from the belly of a colossal beast (despite her constant animosity towards him and continued attempts to kill him) and watching his humble and honorable nature to the most simple of life, she started to question her ways. Finally realizing that Jack was not the enemy, she drops her weapon and reconsiders her purpose, deciding to meditate with Jack on an island from a distance, indicating that she has made peace with the Samurai (Episode XCV)
After returning to the mainland with Jack and learning the true nature of Aku, she sees the error of her ways and becomes his ally, going against her mother and her cult. At the same time, she no longer saw Aku as a god but a demon to be destroyed, finally convinced after being shown solid evidence by Jack that Aku is truly evil. Shortly after, she agreed to help Jack save a group of kids who are being mind-controlled by implanted chips. While Jack distracted the children, Ashi searched for the source of the mind-controlling signal, only to be captured and brought before the sadistic Dominator . While being tortured and forced to watch as Jack is overwhelmed, Ashi was angered when the Dominator gloats about turning the children into weapons due to being naïve and vulnerable, striking a nerve and allowing her to break free of her restraints, since it reminded her too much of how she was also turned into a living weapon for no good reason. Fighting back the Dominator's electric onslaught, Ashi managed to overpower and kill her torturer, freeing the children in the process. Upon discovering that the children are alive and well, Ashi calls out for Jack, but the samurai had mysteriously disappeared. (Episode XCVI)
When searching for Jack on a blimp, Ashi finds herself being targeted by two mysterious figures. When they reveal themselves to be friends of Jack they ask her if she is a friend to Jack as well, leaving her lost in her thought. Ashi then assures them she also wants to help Jack. After hearing the story about how Jack saved the Woolies, the airship captain informs her that Jack got off at their current exit, to which she quickly hops off the blimp. After landing in a forest, she ends up meeting the Three Blind Archers, who tell of Jack's nobleness, then later the Children of Aku, who dance and sing upon being reminded of Jack, causing Ashi to join in as well. Upon arriving at a cave with a waterfall, Ashi remembers how her mother forced her and her sisters to jump into a pile of burning darkness, creating a bodysuit that also allows her to store her weapons. Ashi at first walks away from the cave, but then jumps in and starts scraping the scabs off her body with rocks. While climbing out of the cave, she realizes that she is naked, and creates a new outfit out of leaves. Later on, when she arrives at a tavern in the forest, she meets Da Samurai , who explains that he gave up his samurai life after Jack enlightened him. Back outside, Ashi meets a shadowy person and is asked if Jack is her friend, to which Ashi assuredly says yes. The shadowy person then tells Ashi to follow the path north, after which she finds Jack in a cemetery about to commit seppuku. Ashi tries to snap Jack into his senses, yet The Omen fights to keep her from interfering. Eventually, Ashi is able to get to Jack when she tells him the children from the factory are still alive, allowing Jack to save her from the Horseman and defeat him. After the ghosts of the other samurai return to their graves and Jack compliments Ashi's new dress, she asks what their next move is, and Jack responds it is time to find his sword. (Episode XCVII)
After Jack tells her the story of how he lost his sword, they arrive at the site on the back of a large bird. Exploring the pit, but failing to find the sword, Ashi wonders if someone could have stolen it, to which Jack responds the sword abandoned him and not vice versa. Back outside, Ashi thanks the bird, and it nuzzles her in return. While Jack meditates to find his sword, Ashi remains behind to protect his body. Sure enough, an entire army arrives to kill Jack. Ashi confronts them, much to their amusement, but she actually managed to fight and kill them all. Afterwards, Ashi spots another hostile near the top of the mountain and calls for the bird to take her back to high ground. The assassin fired multiple arrows at Jack, but Ashi quickly catches one mid-air, blocking the rest with a large stone slab. Ashi is surprised that the attacker is none other than her own mother. The High Priestess criticizes Ashi's lack of focus, but offers her another chance to kill Jack. Ashi refuses, explaining that Jack showed her the truth about Aku. Furious, the High Priestess attacks them both, but Ashi manages to defend Jack and herself using only a ram's horn. The High Priestess scolds Ashi for sparing Jack and betraying their family, despite the fact the Samurai killed her sisters. Ashi retorts their fates were already sealed, being raised as nothing more than living weapons. Before the High Priestess can finish Jack, Ashi recovers from the rubble she had been buried under and manages to throw one of her mother's arrows back at her, hitting her in the back and sending her falling to her death. Ashi herself falls to the ground shortly after, exhausted from the fight. Jack wakes her up upon returning from the spirit world. She compliments his new look and getting his sword back, and Jack himself remarks that Ashi has also been busy. When Ashi asks what their plan is now, Jack tells her Aku is their next target. (Episode XCVIII)
After finding Jack's sword, Ashi and Jack journey through a desert, stopping to rest at an outpost resembling a Middle-Eastern-style city. Jack offered Ashi some food from a local vendor, but she politely refused after it temporarily turned his head into a fish. On the camel barge transporting them through the desert, Ashi's affection for Jack begins to surface as they both find themselves being awkwardly hemmed in by multiple green tiger-men. When a trap is sprung, Ashi helps Jack fight their attackers, with the tension between them continuing to rise. Ashi and Jack both agree it's time to leave and escape from the barge, continuing their journey on foot. Stopping at an oasis for water, Jack shows Ashi how to make straw hats for each other, further enhancing their relationship. Eventually, the two are caught in a sandstorm, but find shelter in a towering monolith. Investigating the facility, Ashi and Jack discover it is actually a prison ship, and Ashi is suddenly bitten on the leg by a leech-like creature. Fortunately, Jack kills the creature and removes the poison in time. Hearing an animal-like scream in the distance, they retreat deeper into the prison before confronting their pursuer: A massive monster made of the same leeches from earlier, and barely manage to escape while fighting it off. Shortly after, the duo are directed to the ship's armory, where Jack receives a special weapon that can kill the creature, Lazarus 92 . Unfortunately, Ashi misfires a laser rifle, causing Jack to miss the part involving the weapon's activation. Ashi then dons a riot shield and sword-staff and says she is ready, with Jack reluctantly agreeing. Once they find the creature, Jack attempts to turn on the weapon, but fails. Ashi realizing that Jack doesn't know how to turn it on and tries it herself. In the process, she is attacked by Lazuras-92 and her leaf dress is eaten off, leaving her completely naked. An embarrassed Jack explains private parts are personal, leaving Ashi confused due to her sheltered upbringing and forcing Jack to lend her his gi mid-battle. The two are then surrounded by the leeches when Jack finally activates the weapon and are nearly killed while saying each other's names. After recovering for a moment from the weapon's discharge, Ashi and Jack finally realize their feelings for each other and embrace in a passionate kiss, having found true love together.(Episode XCIX)
Immediately after, Ashi and Jack quickly realize they are kissing and stop, nervous and mildly disgusted by the venom. Ashi offers Jack his gi, but he insists she keep it until she finds new clothes, claiming the ship is drafty. Soon, they spot a hole in the ceiling leading outside. Ashi searches for something to wear while Jack heads back outside. After finding a sweater and boots in a locker room, Ashi comes across Jack showering outside and kindly leaves him his gi. That evening, after hunting some worms for dinner, the two awkwardly try to make small talk. Ashi asks Jack if he ever thinks about his home, and Jack answers that he does so all the time, opening up to her with the memories of his home throughout the seasons. When Ashi asks if there was a girl in his life, Jack explains there wasn't time, since he was only 8 when Aku attacked. While Jack admits the time before Aku's return was nice, the memories of his home are the only way he will see it again. The next morning, a distraught Ashi wakes up to find that Jack has left her again. She later finds him in a robot graveyard, demanding to know why he left. Jack explains that, in addition to witnessing the suffering of many innocent people, Aku has taken everything from him, leaving him with nothing but memories, and doesn't want the same to happen to Ashi. Instead, Ashi assures him they will defeat Aku together. Sure enough, Aku reveals himself, accompanied by Scaramouche. Aku claims he is aware that Jack lost his sword, having learned the information from Scaramouche. When Jack reveals the opposite, Aku telekinetically destroys Scaramouche's head in frustration. He casually prepares to leave as Jack attacks him, but smells something familiar nearby: himself. Ashi arms herself with a sword as Aku approaches her, warning him to stay back. Smelling part of himself inside her, Aku remembers the time when he personally paid a visit to the members of the Cult of Aku, providing them with some of his essence. He then deduces that the High Priestess drank his essence shortly after and gave birth to the Daughters of Aku, revealing to a shocked Ashi that she is Aku's biological daughter. When Jack attacks him once again, Aku simply uses his essence inside Ashi to control her body like a puppet, forcing her to fight against Jack. Jack pleads with her to resist, assuring her she is nothing like her parents, but she is unable to do so. Unhappy with this, Aku throws a giant robot onto them and tells Ashi she needs to "bring out her best" (i.e., himself), corrupting her with an upgraded version of her old outfit. Despite this, Jack manages to break Ashi's sword and cut her arm, briefly getting through to her. Ashi begs Jack to kill her and destroy Aku, but he can't bring himself to do so and stands down. Before Ashi can finish Jack, Aku orders his daughter to stop, joyfully claiming the Samurai's sword as Jack accepts defeat. (Episode C)
As Aku prepares to kill Jack on worldwide television, Jack once more tries to get through to Ashi, though he appears to be unsuccessful. After a period of indecision, Aku decides it's best for Ashi to do the deed. As Ashi prepares to kill Jack, all of the samurai's allies arrive and fight Aku and his forces in a grand-scale battle, while Jack confronts the corrupted Ashi. Eventually, Jack frees Ashi of Aku's control after confessing his love for her. Disowning her father and dueling him evenly with his own powers, Ashi fetches Jack's sword and warps Jack and herself back to the past, to the moment after Aku sent him to the future. Jack then proceeds to destroy Aku once and for all, thus preventing the rise of the demon and sparing both the universe and the future from his tyranny.
Unfortunately, since Ashi was Aku's daughter and Aku no longer exists, she fades away before she and Jack could be married some time later, and falls before reaching the altar. Because Jack had altered history, her path was altered as well, and she disappeared from his arms. (Episode CI)
- Ashi will meet Pooh, Ash, Littlefoot, Simba, Alex, Sora, Tino, Otis, Thomas, Twilight and all their friends in Pooh's Adventures of Samurai Jack (Season 5).
- At the end of the series, Mewtwo, the Good Fairy, and Zordon will summon the great dragon spirit Shenron (who also revived Zordon) who will resurrect Ashi with all of her memories and powers (excluding the Time Portal power) and will permanently remove her from Aku's bloodline as well as what's left of his evil essence inside her.
- After her resurrection, Mewtwo, Aisling, Zordon, and the Good Fairy will become her new family and will join the 100 Acre Wood Rebel Alliance.
- Ashi is also set to make her appearance in Thomas' Adventures Chronicles.
Ashi's adopted father. While he's not romantically in love with the Good Fairy, they both agreed to raise her just like how they do with Aisling.
Ashi's adopted mother. While she's not romantically in love with Mewtwo, they both agreed to raise her just like how they do with Aisling.
Ashi's beloved, adopted little sister.
Her adopted grandfather.
Best friend and trainer.