Kaato is Norisuke Higashikata IV's former wife and the mother of Jobin, Hato, Joshu and Daiya Higashikata. After being condemned to 15 years in prison for the murder of a child, she is released and determined to be duly compensated for her time spent in prison.
Kaato is a 52-year-old woman with shoulder-length black hair, parted in the middle with two spiral buns on each side which end in two spiraling pigtails.
She wears a long dress with a layer of fringe along the waist and with playing card back designs with the Higashikata family crest across her chest and on her hips. She also wears large rectangular bracelets on both of her wrists.
Kaato is a very mysterious individual, showing different sides of herself depending on whom she's speaking with. She seems to act the most genuine around her son, Jobin Higashikata, whom she has a special connection with. Since he was a boy, Kaato doted on Jobin and would take special care to make sure he was always alright.
Kaato herself acts incredibly loving towards her children and claims to never have stopped thinking about them during her 15 years in prison. However, she is not above violently attacking them if she is disrespected, as shown when Joshu intentionally tripped her with a chair and she relatiated by making a chair appear and stab him in the chin. Kaato states that all human are born unequal, and that everyone tries to climb to find happiness. She pushed Jobin into committing to ambition to make him climb "higher". For that she was ready to sacrifice one of Jobin's bullies to cure him from the Rock Disease. Another reason for her act is that she wished to decide her fate for herself, seemingly disapproving of being de facto the one who would sacrifice herself for Jobin's sake.
When Kaato steps out of prison, she is revealed to be determined in being granted her due "reward" for sacrificing 15 years of her life for the family. Thus, she demands that Norisuke gives her half of his fortune for the divorce (claiming that half of the Higashikata House is hers), and she also wants to spend more time with her children. On a more humorous note, she is also seen "breaking" into the property and treat it as if she still belonged her, watching the TV in the living room or sunbathing in the garden with some champagne.
- Main article: Kaato's Unnamed Stand
Kaato's Stand appears to take the form of a simple deck of playing cards. However, by placing objects between the cards, she can store that object in the deck itself as if nothing was there. Once stored, if a card containing the object is flipped over the object will emerge.
The size limit of objects Kaato can store within her cards is unknown, though she was able to keep a full-sized dining room chair within them.
Fifteen years ago, Kaato Higashikata was a loving housewife to Norisuke Higashikata IV and her family. Sharing an especially close connection with her son, Jobin, she'd take special care to make sure he was safe as a child, due to his developing Rock Disease. Unbeknownst to her, Jobin was secretly being bullied by his fellow boy scouts; one of whom forced Jobin to steal Kaato's underwear and take candid photos of her in the shower. Discovering Jobin's bully situation, Kaato approached her son after he awakened his new Stand. She had Jobin accompany her as she stored the bully's unconscious body in her car's trunk.
Driving to the location of a shrine, Kaato intended to save her son's life by sacrificing the bully to cure Jobin's Rock Disease. Instructing him to "keep climbing" and leave others "at the bottom", she had Jobin bury the bully alive underneath the shrine. Five years later, the bully's corpse was found and DNA evidence was linked to Kaato and her vehicle. Saving her son once again, she was arrested and imprisoned in Morioh's Stone Ocean prison for 15 years. During her imprisonment, she was divorced by Norisuke for the murder charges. While she served her time, her fate was falsified by Norisuke to his children, being told that their mother was dead so they wouldn't have to bear the shame of Kaato's crimes.
She is released from prison on time served shortly after her family's encounter with Tamaki Damo. The guards warn her that society has likely not yet forgiven her for her crimes, but they all loved her dearly. As she gets dressed in her original clothes, she retrieves a deck of cards she was allowed to have while imprisoned, which reveals a cellphone hidden within them, a result of her Stand's ability to hide things within the deck. She calls someone on the phone, who promises to pick her up at the prison, but she asks the caller to keep her release a secret from the family, as she wants to surprise Norisuke. As she hides the phone back in the deck of cards, Kaato claims she has no regrets for what she did as she plans on taking the life she lost back, and her caller is revealed to be her son Jobin. She leaves Stone Ocean prison, tossing her engagement ring from Norisuke in the air as she walks out a free woman.
Kaato later meets up with Jobin, who allows her into the Higashikata household. Kaato waits on the couch for several hours as her children wonder who she could be. Once Norisuke wakes up, she calmly greets him to his utter horror. She lovingly introduces herself to the family, explaining that she is their mother. As Norisuke demands to know why she is out of prison and specifically returned to the household, she swears on her ancestors that she was an innocent woman and simply wanted to be reunited with her family. She then reveals that Norisuke divorced her while she was in prison while Hato explains to Josuke that Norisuke lied to them over their childhood; claiming that Kaato had died or abandoned the family. Joshu is less enthusiastic about meeting his mother and purposefully kicks a chair into her as she goes to hug Daiya. Joshu then undresses Kaato using Nut King Call to humiliate her further. The action causes her deck of cards to fall from her bra and spill out on the floor. Kaato, feigning worry, asks Joshu to help pick them up. As Joshu flips over a card, he is suddenly struck on his chin by a chair leg that was hidden between the cards. Kaato then warns Joshu not to trifle with her ever while still reaffirming the other children of her love for them. As Jobin enters the household, Kaato politely excuses herself to her hotel; saying that she'll come back when everyone is less shy.
Kaato later appears painting her nails while sunbathing in Norisuke's hammock and drinking his stash of Champagne Krug, much to his surprise. He commands her to leave immediately while she states calmly that half of the house, and Norisuke's assets, still belong to her. After Norisuke storms off, Kaato calls Jobin on her phone, telling him that she suspects Norisuke is plotting something. She also informs Jobin of Josuke's interloping, correctly assuming that he's also working against them.
- Kaato's wedding ring has "N to C" engraved on it. If the letters are referring to Norisuke and Kaato's initials, it would suggest that her name is meant to be romanized with a C instead of K.
- In Japanese, "Kaato" sounds similar to the Japanese pronunciation of the word "card", keeping with the names of women in the Higashikata family being based around playing cards, along with both her daughters, Daiya and Hato and her daughter-in-law Mitsuba. The only missing suit being the Spade, which Tsurugi may be, given that in some versions of the game replaces the Spade suit with Sword, which is the meaning of Tsurugi's name.