Loner (9/15/2015 – 1/15/2016)
She stars as the main antagonist of Yanderetale.
Oka will not be present at school for the first three weeks of the game. While she is absent, Shin Higaku will be her substitute, and he will allow the player to join the club and participate in club activities while Oka is absent.
Until the August 18th 2018 Build, the player was able to see Oka walking around, but her current features and routine were temporary and will change in the future.
Oka's first hairstyle in the November 15th, 2015 Build was exactly the same as Sakyu Basu's, except with hair covering her left eye. It was dark purple.
As of the December 2nd, 2015 Build, she has messy, shoulder-length hair that is dark navy blue. She has a fringe hanging down the middle of her face, flowing across her right cheek. Her eyes are light purple. She has large black rings around her eyes due to lack of sleep. Her lips and skin are pale, and the upper half of her face is slightly shadowed. Since she is a club president, she wears a "Red Armband of Leadership" on her left arm. Her bust size is 1.
Like all Occult Club members, Oka wears a black choker. However, instead of having a crescent moon on it, it has a silver spider. If the Occult Club disbands, she will not wear the choker anymore.
She walks very slow, with her hands clasped together. Oka is always looking shyly at the ground. As of the June 1st, 2016 Build, Oka wears light blue-grey thigh-high spiderweb stockings and fingerless gloves. Her panties are also black. In the future, Oka will have very pale skin. According to her full body reference, it appears that in the future, Oka will have a pentagram drawn on her armband.
In Oka's original design, she was supposed to wear a turtleneck underneath a dark blue blazer. It was scrapped because Oka's model could not support two models of clothing at the same time. As of the April 10th, 2017 Build, Oka can wear this outfit by pressing the A key in the easter egg menu.
YandereDev stated that she may be the shortest rival.
"Oka is the president of the school's occult club. She is completely convinced that ghosts, demons, and black magic really exist, and wants to dedicate her life to proving that these things are real.
Oka is absent for school during the first three weeks of gameplay for mysterious reasons. As soon as she returns to school, she is immediately smitten by Senpai. Due to the fact that she falls for him in an extremely short span of time, she believes that there must be something supernatural about him, and begins studying him intently.
She is an awkward girl who is regarded as 'creepy' by the majority of the school, but she is actually quite harmless, and some people even find her to be endearing, as she is quiet and thoughtful. Perhaps Senpai will think that there is something charming about her unusual nature..."
Oka is a stalker, but not a yandere, as she is too shy to harm others. Her mannerisms are meant to make her look shy, timid, and socially awkward. She has been obsessed with anything paranormal since early childhood.
Among the personas currently implemented in the game, she is a Coward. If Oka sees a corpse, she will flee from school and call the police. If she witnesses a murder she will start begging the player to spare her life in exchange for her silence. She cannot participate in physical fights against murderers. It is unknown if she will be given a different personality later on in the game, due to the fact that some rivals may have the Lovestruck persona. Because she is shy, she will hide her face if the player aims their phone at her.
Oka's default reputation is -3.
Oka can be seen walking around and looking at the scenery in the street. She can also be seen looking towards the ocean on the edge of the town.
In her first appearance at school from the game, Oka would enter school grounds at 7:05 A.M. She would then walk to her locker at 7:10 A.M. and change from her outdoor shoes to her indoor shoes. At 7:15 A.M., she would walk to the rooftop and stalk the Basu sisters in search of proof that they are actually supernatural beings, as stated by her Student Profile. If both sisters were dead, then she would stay in the Occult Club room until class began instead.
At 8:00 A.M., Oka would walk into her classroom and sit at her desk. She would then start her morning classes at 8:30 A.M.
At 1:00 P.M., she leaves class to go to the Occult Club. She would walk back to class again at 1:30 P.M. and participate in cleaning time between 3:30 P.M. and 4:00 P.M. She would then head to her locker and linger there until 3:50 P.M., where she would head to the Occult Club again and stay there until the end of the day. If Ayano Aishi joined in on club activities, Oka would unsuccessfully try to summon a demon with other members of the club from 5:30 P.M. to 6:00 P.M.
In the case of the Occult Club’s disbandment, she would socialize with the other remaining former members outside of the club when she would normally attend it (1:00 P.M. and 3:30 P.M.).
The topics towards Oka are (Negative/Positive/Neutral) as follows:
- Martial Arts
- Everything else.
— Talking to Oka.
She is the founder and president of the Occult Club. As with other leaders, the player will have to talk with her to join. If she dies, or less than five members of the club remain, the club shuts down. Any club members who witness the player's crimes will report to her, and Ayano will be either kicked out or unable to join the club. In the future, if the club has disbanded before her designated week arrives, there will be a short cut scene about this, and she will express some very sad feelings.
Relationships and Bullying
The Basu Sisters
She truly believes that they are supernatural beings, and dismisses any evidence that suggests otherwise.
- Main Article: Senpai
Since she is a future rival, she will have a crush on him and will confess to him on Friday. Oka is a very superstitious person, which might play a role in how she develops a crush on Senpai. Since she is very strange, the way they will meet will be comical.
If she entered a relationship with Senpai, he'd become a paranormal investigator.
- Main Article: Shin Higaku
Oka trusts him to operate the club when she is not present, according to his Student Profile.
- Main Article: Suitors
In the future, Ayano can matchmake Oka with her suitor.
Main Article: Sumire Saitozaki
It is possible that one Oka's eliminations will involve Sumire.
Some students gossip about the Occult Club to say what freaks they are. It is also rumored that Oka does self-harm.
- Oka may walk around in circles, pausing every once in a while, while stalking the Basu Sisters. This can be fixed by bumping into her.
- In his Q&A, YandereDev stated that she isn't a huge fan of anime, and prefers "verifying what exists and doesn't exist in the real world, rather than fictional worlds". He also commented that she is interested in extraterrestrial life. There also was a question about killing her, and Dev said that "In eliminating her by killing, her clubmembers will play a role, but there will be other factors too". He prefered to not spoil more.
- She was implemented in the November 15th, 2015 Build.
- Her favorite "creepypasta" is anything popular on the Japanese internet in the year that the game takes place.
- In November 2015, YandereDev said that one of the rivals may be a student who has anxiety and is always paranoid. This description resembles her.
- Oka's name is a play on the word "Occult" when transcribed into Japanese Katakana: Okaruto (オカルト)
- There's also a Japanese name "Oka" (黄花), which means "Chrysanthemum". The word "Oka" also has different meanings, which include "Hill" (丘), "Height" (岡), and "Knoll" (壟).
- YandereDev finds Oka very cute,and has stated that he thinks she is the cutest rival.
- Oka was first created through a suggestion thread. In one of the first "suggestion threads", someone pitched the idea of a goth girl rival. The girl who first popped into YandereDev's head was a shy, cute girl.
- One of Oka's elimination methods may involve Sumire Saitozaki.
- Oka has played Corpse Party before.
- According to YandereDev, she is "one-third" Hex Maniac from Pokémon X & Y and Pokémon Omega Ruby & Alpha Sapphire, "one-third" Tharja from Fire Emblem: Awakening, and "one-third" Tomoko from WataMote.
- Oka was the only NPC who had a custom walk animation. It was the same animation used when Ayano stands near Senpai. This walk animation was removed in later builds, however, YandereDev eventually realized it was missing and re-implemented in June 1st, 2016 Build.
- Oka makes a cameo in the Gaming Club by appearing in the stealth game. She is shown stalking Rival-chan and Mai Waifu.
- YandereDev's current reasoning for Oka being absent in the first 3 weeks of school is that she had to deal with some very important personal business.
- Oka's dark secret may be related to the reason for her absence from school for the first few weeks.
- Originally, Oka may have been planned to be the fifth rival instead of the fourth, as in the original rival silhouettes, she was placed fifth instead of fourth.
- Oka won't clean the third floor bathroom due to rumors of it being haunted.
- YandereDev thinks it would be appropriate for her to haunt the school if she was killed.
- In the future, it may be possible for Oka to be visible as a ghost after she is killed.
- She is YandereDev's favorite club leader.
- YandereDev thinks that she is currently the only club president to have founded their club.
- As of the August 18th, 2018 Build, she is no longer in the debug builds. She will make her true appearance in the final game.
- As of the October 17th 2019 build, she appears in the town as a background character.
- Oka's parents probably own a business with a name like "Spiritual Consultation" where they offer services like exorcisms, seances, fortune telling, spiritual advice, but they aren't con artists, and genuinely believe that they are actually providing real, meaningful help to their clients.
- It is rumored that she does self-harm. It may be possible, but as for now not proven true.
- She was added in the game before she was a rival because YandereDev had edited one of the pre existing unity hairstyles (Sakyu Basu's) for it to look gloomy, and since Oka was a gloomy character, he added her into the game with the edited hair.
- Oka was the first rival added into the game.
- There is a rumor at school that Oka asked each of her clubmembers to pluck out one of their own eyes so that she could perform a demon-summoning ritual that requires a sacrifice of 5 eyes. However, these rumors have never been confirmed.
— Speaking to her while she's inside the club.
— Leaving the conversation while she's inside the club.
|“||...y-you... actually... want to join...?...||”|
— Asking to join the club.
|“||...this is wonderful news... perhaps the world isn't such a dark and lonely place, after all... um... anyway... you're an official member now...||”|
— Joining the club.
— Refusing to join the club.
|“||...y-you're not... going to leave us... are you...?...||”|
— Asking to leave the club.
|“||...well... that's to be expected... I mean, who would want to be in this club, anyway....||”|
— Leaving the club.
|“||...oh... that's a relief...||”|
— Deciding against leaving the club.
|“||...we are devoted to the research of supernatural and paranormal phenomena... witches, ghosts, vampires, demons, aliens, psychics, and time-travelers are all welcome here. Anyone who joins our club will develop a resistance to horrific and terrifying things... or succumb to them... heh heh heh...||”|
— When asking Oka about on information of her club.
|“||...um... you can't be... in two clubs at once... I'm sorry...||”|
— Trying to join the Occult Club after joining another.
|“||... the moon is not in position yet... come back between 5:00 and 5:30...||”|
— Trying to participate in club activities too early.
|“||... we're going to attempt to summon a demon again... will you help us...?...||”|
— Asking to participate in club activities.
|“||...excellent... I hope it works this time...||”|
— Participating in club activities.
|“||... oh... well... we can wait... but no later than 5:30...||”|
— Deciding not to participate in club activities.
|“||... I'm sorry... the moon is no longer in position... the ritual can only be performed between 5:00 and 5:30...||”|
— Trying to participate in club activities too late.
|“||...you can't be here... your aura is too dark...you will attract evil spirits... I'm sorry... please leave...||”|
— Talking to Oka after she has witnessed Ayano murder someone.
|“||... I'm sorry... one of our members believes that you may be possessed by a demon... I can't allow you to join this club... please don't hurt me, demon...||”|
— Talking to Oka after an Occult Club member has seen Ayano kill someone.
|“||... um... I'm sorry... you can't be a member of this club anymore... you're too scary... huh, that's ironic... being kicked out of a club about scary things... for being too scary...||”|
— Talking to Oka after an Occult Club member has seen Ayano kill someone while you're a member of the club.
|“||...um... you already left this club once before... I... don't want to let you back in... you might just leave again... and it hurts when people leave... I don't want to be hurt again...||”|
— Asking to join the club again after leaving the club.
|“||..we're about to summon a demon... would you like to join us...?...... I can't stop thinking about that boy... I think he cast a hex on me...||”|
— Oka in "Yandere Simulator Rival Introduction Video" 
|“||You're just in time. We're about to summon a demon... would you like to join us...?...... I can't stop thinking about that boy... I think he cast a hex on me.||”|
— An alternate line for Oka for the "Rival Introduction Video".
|“||... I've been expecting you... you're here to kill me, right? ... I knew this day would come... but... just so you know... I won't go down without a fight.||”|
— Oka in the introduction cutscene of Yanderetale.
|“||U-Um....Uekiya... if you don't mind me asking... I was wondering... w-what kind of evil spirits are you trying to ward off...?
W-Well... the flowers in your hair... those are charms to protect you from the vengeful spirits of the dead... r-right...?
O-oh... s-so there aren't any ghosts haunting the gardening club...?
W-well... in a way... picking flowers and wearing them in your hair is kind of like committing a mass slaughter and then wearing the corpses of your victims as decorations... d-do you ever worry that the ghosts of the slain flowers will come after you?
N-no... t-today, I'm the same as I always was.
|“||...a...f-flower? ...for...m-me? ...are you sure? ...I mean, nobody's ever...it's really...I just...um...th...thanks...||”|
— Hypothetical dialogue of Oka reacting to someone giving her a flower.