Nazo no Kanojo X Wiki

" Ueno and I kissed again yesterday . . . . "


Ayuko Oka is a classmate of Urabe and Tsubaki, Ueno Kouhei's girlfriend (he calls her Ayu) and Urabe's eventual intimate, Shouji Ai friend. She was first introduced in the anime and manga when Tsubaki walked into an empty classroom to see her and Ueno kissing together.

Physical appearance

Oka is very short (only 143cm tall / 4 feet 8 inches tall), and therefore she has a body which resembles that of an innocent little girl, yet she has a quite large breasts and an hourglass figure like that of an adult fashion model, giving healthy boys like her boyfriend, Ueno, mixed feelings about her appearance. She has a round face with a slightly pointed chin, and big 'anime girl' style eyes that are partially hidden behind the fashionable style glasses that she always wears. Her eye color is that of a deep, mysterious purple. Oka has short very dark chocolate hair with milk chocolate highlights, that she always wears in a cute, pixie cut that emphasizes her casual, but attractive style. She as a medium beige skin tone that is very even throughout her body. She has short arms, plus short legs that look longer since she always wears booty shorts or mini-skirts.

She is very fashionable, and tends to wear attractive, though somewhat revealing, clothing out in public, much to the displeasure of Ueno. But that is just her personal style. Like Urabe, Oka wears bikini swimsuits to the beach, such that Ueno is reluctant to take her for that reason. Oka follows the latest fashion trends for teenage girls, and is always trying out some new fashion that is the latest style in popular culture. She also loves to cosplay, and gleefully wore a French Maid's outfit in the maid cafe during the Hoshinome School Cultural Festival.


Oka has remarkable self-worth and self-confidence. She can be bold and intimidating in both her attitude and appearance. She seems to 'call the shots' in her relationship with her boyfriend, Ueno, and at times will dominate over him. However, at other times, she is willing and able to become subservient to him, thus causing Ueno to always be uncertain as to her mood and behavior. Although Oka and Ueno seem to have a typical girlfriend and boyfriend romance, secretly, they enjoy a playful, fun S&M relationship, with the two changing the master and servant roles frequently. Oka is also portrayed as being slightly devious, this given by her positive reaction and joy in peeking down Urabe's blouse one day, and seeing her lacy bra.

Oka is also a bit of an exhibitionist, as she likes to wear sexy, provocative clothing in public, much to the chagrin of Ueno. Although Oka likes to 'show off' by wearing her peculiar fashion style in public, she is actually entirely loyal to Ueno. This is seen when she had considered a shipping with Tsubaki, but declined in her mind to do so, as it would be distressing and unfair to Ueno. Oka is also somewhat competitive, especially in social and romantic situations. She wishes to always stay ahead of what Urabe and Tsubaki are doing romantically, as if it were a competition of sorts. However, Oka also has a strong sense of friendship, especially with Urabe who she shares a drool bond with, and considers the bonds of friendship to be unbreakable, even to the point that Oka likes to, at times, tease and spoof Urabe and Ueno.

Despite Oka's somewhat rebellious nature, she applies herself to her academic pursuits, and gets good grades and praise from her teachers. She even consents to regularly tutor Ueno, who only looks upon her study sessions as time to attempt to make-out with her. Without Oka's concern and empathy for Ueno's downward academic direction, he would probably fail high school.

Oka loves sweets, especially ice cream, and loves to go shopping for new clothes, or to spend a day at the beach.

Oka's Story

Oka likes to wear daring, revealing clothing styles out in public, that call attention to her, something that greatly concerns her boyfriend, Ueno. Note the sexy bare midriff on the outfit that she wore while shopping one day.

Oka attends the same High School, and is in the same classes as Urabe and Tsubaki. After she sees the drool-tasting ritual between Tsubaki and Urabe, she befriends Urabe, and tricks Urabe into sharing a girl-with-girl drool bond as well. Later, Oka very casually and slyly tastes Tsubaki's drool infused ice cream, and also forms a casual drool bond with him, after all. She views her relationship with Ueno almost as leading competitors with Urabe and Tsubaki for social and romantic progress. Although in episode 6 of the anime she does "flirt" with Tsubaki by calling him by his first name and touching his face, which could lead some people to believe she might like him. However, she later tells Urabe in confidence that even though she was romantically attracted to Tsubaki, she decided that a relationship with him would be 'problematic', especially since she already has a somewhat jealous boyfriend, Ueno. Although Oka eventually forms a casual drool bond with Tsubaki, she nevertheless keeps him as a social friend, but keeps him 'at arms length', so as not to trigger any jealously or resentment in Ueno, since Ueno and Tsubaki are best male friends themselves.

Oka wearing her maid's costume at the Hoshinomi Cultural Festival. After secretly seeing something very profound, she is being kept quiet by Urabe, inside the robot costume.

Oka has a passion for cos-play and possibly cross-cosplay. This can be seen from when she is offered to dress as a sexy French maid at the Hoshinome Cultural Festival, she is eager to do so, even to the point of helping out at the Maid Cafe. She rejoiced when high school boys wanted to take pictures of her at the Maid Cafe, although this sparked rabid jealousy in Ueno. Later, Oka, as a guilt offering, offers to wear the French Maid outfit out in public, with him on a date, calling him 'Master' all evening long. Ueno objects, but secretly is pleased at her offer of a date with him and his devotion to her.


Oka is of small stature and physique, much like that of a child. In the Japanese language, the first name 'Ayuko' is feminine, and means a loving, affectionate, fragrant child of the evening, or tender and gentle child of the rainbow.


More about Oka can be found by clicking on---

Omake ( extra content ) by Riichi Ueshiba

Characters With Drool Bonding

Oka's gallery