|Role|| Yandere-chan's Mother (2018)|
|Age|| Around 17 (1989)|
Around 46 (2018)
|Strength||Dependent on Physical Education|
Ryoba Aishi is Yandere-chan's mother and the wife of Yandere-chan's father.
It has been confirmed from the first Basement Tape that Ryoba is the same girl featured in the Mysterious Tapes whom The Journalist confronted. She will be overseas for 10 weeks for Story Mode because she is chasing down The Journalist, as said in Basement Tape #10. She will be playable as the main protagonist of 1980s Mode.
"Ryoba Aishi is the mother of Ayano Aishi, the protagonist of Yandere Simulator. Ryoba attended the same school as her daughter in the late 80s. She has lived in the same neighborhood for her entire life.
She is a cheerful and friendly woman who seems to get along very well with everyone in her neighborhood, although nobody seems to know very much about her, not even her next-door neighbors.
She is a very private woman who never talks about herself, and never divulges many details about her occupation...but she's always willing to talk for hours about her husband and how much she adores him."
BackgroundBefore Ryoba met her senpai, she was the same as her daughter. She moved through life with no purpose and thought without emotions, only logic.
Eventually, Ryoba met Yandere-chan's father in the 1980s at Akademi High. Ryoba was a yandere, and killed the Phantom Girl with a knife in the third floor girls' bathroom. As revealed by a series of tapes, her activities - using manipulation, intimidation, and sometimes even violence to bring about the disappearances and expulsions of her upperclassman's admirers - were discovered by a suspicious journalist who had taken it upon himself to investigate the murder when the police were forbidden from conducting a formal investigation. Ryoba was arrested and accused of committing numerous crimes, but was able to not only deflect the charges but sway public opinion in her favor by playing the part of an innocent girl being stalked and falsely accused. Ryoba used the court case to simultaneously become a media darling and irreparably ruin the Journalist's reputation, and after she was acquitted of all charges she cornered the Journalist and warned him to never cross her again, as it would be too easy to make his death seem like a suicide.
Soon following this, as revealed by Basement Tape #1, Ryoba abducted her upperclassman, tied him to a chair, and forced him into a relationship with her, revealing that her mother had done the same to her own crush, implying that she was a yandere too. Ryoba eventually married her upperclassman, giving birth to a single daughter. She has no other children other than Yandere-chan.
Ryoba never moved out of her home town or gave up her yandere habits, as almost thirty years after the investigation she was discovered by the Journalist stalking a young woman fresh out of high school. Realizing the Journalist had returned, Ryoba lured him into an alleyway and ambushed him. After this, he fled Japan and left for America. Ryoba and her husband then packed their bags and went to America as well to hunt down the Journalist.
As an adult, Ryoba has a gentle face with waist-length black hair tied into a ponytail with a parted bang and two long pieces of hair on either side. She has grey eyes. When her true nature shows, her eyes become empty and soulless, and she dons a disturbing smile.
As an adult, she wears purple, her husband's favorite color. In her illustration, she wears a light purple apron and slippers, she has a dark purple t-shirt and dark blue jean pants. As a teenager, Ryoba resembled Yandere-chan, but with much longer hair, tied in a ponytail, reaching past her waist. She wore the default female school uniform and black stockings.
Being a yandere, she is clingy and paranoid, needing to kidnap her senpai even after getting rid of her rivals.
She is cunning and was able to murder her 10 rivals, get away with her crimes, and be able to kidnap her senpai. She was able to fool all of Japan into thinking she was innocent and that the Journalist was the villain.
Mysterious Tape #3 displays that her methods were well-rounded and that she could effectively bully, expel, and keep students from coming to school. She used a variety of elimination methods to achieve her goal.
- Main Article: Yandere-chan
Yandere-chan doesn't have a negative relationship with her parents. YandereDev states that she's just indifferent to them. Yandere-chan believes her mother to be a lovely and innocent human being, though she may not know what her mother did in the past. Yandere-chan's mother loves and adores her daughter very dearly because she is a physical manifestation of the love between her and her husband. The mother knows about Yandere-chan's lack of emotion.
Knowing that her daughter has just reached the same age as when Ryoba got her Senpai, Ryoba would be very curious to know if Ayano is going through a similar experience. Ryoba may call Ayano every Saturday just to check on her dear daughter. During these checkups, she would learn that her daughter has found someone special. She would be extremely excited and give advice that relates to subjects such as reputation. Also, Ryoba would mail useful gifts to her daughter.
If Ryoba sees Yandere-chan romanticizing a female Senpai, she would be delighted to see that her daughter has found "love" with someone. Her mother gets her values from her own experiences.
YandereDev has stated that he believes Ryoba may have hinted to Yandere-chan how to get away with murder without being up front about it.
She would have aided Yandere-chan with her crimes if she was still in Japan at the time.
- Main Article: Yandere-chan's Father
Ryoba's background was revealed in the Basement Tape. During the 1980s, she kidnapped her senpai and held him hostage. It is revealed that she absolutely loves him, while he doesn't have the same feelings for her back. She eventually married him and had one daughter, Yandere-chan.
Even after having a daughter, he is still afraid of his wife. When he thinks he has accidentally said something wrong about his extremely quiet daughter, he quickly corrects himself before Ryoba can truly notice. Basement Tape #10 proves that he doesn't dare go against her, and is submissive to the decisions of his wife.
She and her husband were revealed to have argued when it came to the topic of Yandere-chan's childhood lack of emotion, as Ryoba didn't see an issue, while her husband did. 
Ryoba didn't 'mind-break' him because she felt pity for her mind-broken father.
- Main Article: Phantom Girl
- Main Article: The Journalist
Their backstory and how they interacted is told throughout the Mysterious Tapes. There's some more information on the Basement Tapes.
Ryoba doesn't kill The Journalist right away after the court case and he lives until sometime shortly before Yandere-chan's first day of high school, as seen from Basement Tape #10. Ryoba follows him to America, but it's currently unknown what happens next.
- YandereDev has not decided if Ryoba will have any siblings.
- He will not say "yes" or "no", as saying yes may create more lore and saying no will rule out a sequel starring Yandere-chan's cousin. 
- Her name was revealed in Basement Tape #1.
- The first Basement Tape may have implied that Ryoba raped her husband. When asked about this on Twitter, YandereDev said that he would like to address this issue with a tape so it would not be spoiled on Twitter.
- The Japanese word for "matron" is "ryōbo (寮母)". The name was changed to Ryoba so it would sound more feminine. When translated, "ryōba (両刃)" is a type of Japanese saw which means "double blade" in English.
- She never left her hometown, so it was easy for The Journalist to find her after several years, as said from Mysterious Tape #9.
- The player might get to see Ryoba in action in a brief ending cut-scene of Story Mode, but it would depend on budget and volunteers.
- There might be a specific cutscene between Ryoba and Yandere-chan if the latter uses pacifist methods in eliminating her rivals.
- There are three times Ryoba will make an appearance, in one of the game's endings, in a post-credits sequence, and in "1980s Mode".
- Ryoba and the CEO of Saikou Corp have spoken before.
- YandereDev has said that in the game's future skirt inventory, the skirt was made by Ryoba and was given to Yandere-chan, who declined, seeing no use for it. However, after meeting Senpai, Yandere-chan managed to find many ways to use the skirt, and began wearing it on the first day the player gains control of her.
- Her husband's favorite color is purple, so she wears purple.
|“||Long time no see, Mr. Journalist.||”|
— Mysterious Tape #10. The Journalist quotes her words.
|“||Oh, darling! You're finally awake!||”|
— Basement Tape #1. What she first says to her kidnapped senpai.
|“||Watching you sleep is always fun, but it gets a bit old after 6 hours, you know?||”|
— Basement Tape #1. Ryoba cementing the fact that she's insane.
|“||Say. My. Name.||”|
— Basement Tape #1. After she politely asks the father to say her name and then gets a bit angry.
|“||Victim? Of course not, darling! You're the one I was protecting this whole time! That's right, darling! They were threatening our love! I had to get rid of them all.||”|
— Basement Tape #1. After the father is unsure if he's going to die.
|“||Sorry, darling! You're not allowed out of that chair until I'm 100% sure that you'll never try to leave me! From this day forward, I'm never going to let you out of my sight! We'll be together...forever!||”|
— Basement Tape #1. Denying the father freedom from the chair.
|“||Oh! Are those our old tapes? The ones we made back in the 80s? *Giggle* Did you get a bit nostalgic for the good old days?||”|
— Basement Tape #10.
|“||Oh, my! Are you jealous, darling? Are you worried that someone is going to steal your beloved wife away?||”|
— Basement Tape #10. Jokes that the father is jealous of The Journalist.
|“||That's right, darling! Pack your bags! We're going to America!||”|
— Basement Tape #10. She excitedly tells the father that they're going to chase down The Journalist in America.
|“||If our daughter is anything like her mother, she'll have absolutely no problems whatsoever taking care of herself! Oh! I hope she meets someone special! It would be so nice if she's gotten a boyfriend by the time we get back!||”|
— Basement Tape #10. After the father asks what will become of their daughter while they're away, Ryoba says it'll be fine.
|“||Don't wait for him to make the first move; while you're waiting, some other girl might snatch him up. You need to be proactive about this sort of thing! / If another girl starts competing for him, don't back down. Stand your ground and fight with all your might! Don't let anyone steal your man! / Be mindful of your reputation. If everyone is saying bad things about you, he won't be able to respect you. Try to make lots of friends!||”|
— Hypothetical dialogue of Ryoba giving Ayano advice for her Senpai.