Eiko has long straight black hair that is accessorized by a pink headband with bangs going on either side and gold-orange eyes.
Eiko is a very kind, polite and well mannered young woman who does not seem to be aware that her way of shortening her previous occupation, Animal Video, causes misunderstanding.
Not much is known about Eiko's past, except that she used to work as an Animal Video actress, but she soon quit her job to apply for one where she would be to see the smiles on the customer's face personally.
Eiko first appears in Isuzu Sento's dream as an applicant for the secretary position, where Seiya Kanie hires her and remarks that her big-sister charms will comfort him in his darkest moments. She then drapes herself over his shoulder, to which he remarks that the pressure of her breasts against his shoulder feels good. Later, when Seiya, Moffle, and Isuzu are really holding the interviews, Eiko is the first applicant to be interviewed, her appearance stunning Isuzu with the similarity to her dream. She doesn't seem put off by Moffle's appearance, who is not wearing a Lalapatch charm, and is completely calm. Seiya notes that she asked for positions with a lot of guest interaction, and she tells him she worked with a talent agency called Quattro Productions. When asked what they produced, Eiko tells him that they made AV's, stunning the three interviewers. She herself doesn't seem bothered by their reactions and merely remarks that she gets reactions like that often when Seiya apologizes. He asks her why she wants to work at the park, and Eiko answers that while she enjoyed her last job, she wanted to see the smiles on her customers faces. She gets hired after the interviews, along with Biino Bandō and Shiina Chūjō. Later, Isuzu sends Eiko a message asking for her stage name and a list of prior roles from her former agency. She sends Isuzu the information, and when Isuzu searches up the titles, it's revealed that when Eiko said she made AVs, she didn't mean "Adult Videos", but "Animal Videos".
In the Monthly Report, having been hired, she's seen working in Moffle's House of Sweets.
She makes a few brief appearances in Volume 3, when she meets Shiina for the first time. Eiko talks to her a little and stuns Shiina by telling her she used to star in AVs, saying that she wishes she knew why everyone was always so surprised when she said that. Thinking she means "Adult Videos", Shiina instantly begins to respect her, feeling like she's grown up a lot just by sitting next to her. When Biino collapses from blood loss, Eiko in the only one of the newcomers who remains calm as the staff carries her out. When Eiko is assigned to Macaron's Music Theater, she waves to Shiina as she leaves, making Shiina want to call her "Big Sister" because of her kindness.
When Shiina is transferred to Macaron's Music Theater, Eiko goes to Moffle's House of Sweets in her place.
Later, at the cast party after Shiina sings, Eiko and Biino come and congratulate her. Shiina is happy about this, and she hopes she can be friends with the two of them.
Eiko makes another few brief appearances in Volume 4. When Biino slaps herself in the cheeks so hard, she accidentally gives herself a nosebleed, Eiko and Shiina come and ask if she's okay. Biino thinks that when Eiko says she starred in AVs, she means "Authorized Versions", or video versions of Bible stories. Eiko and Shiina tell her that they are worried about her because they heard that there was a curse on her. Eiko advises her not to be so hard on herself, and Shiina says that she knows Biino will get better. When Biino tries to convince them that she's feeling better, Eiko tells her that she's clearly forcing it, but Biino runs off before she can push the matter. When the Amaburi crew are in the middle of trying to remove Biino's curse, it's mentioned that Eiko and Shiina have the ability to resist the curse.
When Triken is making a PV for the park, he goes to the part-timers for suggestions. Eiko says that the video was wonderful, but it lacked uplift. When asked to give an example, she suggests equestrianism, stating that she recieved a video of a horse giving birth, and that it was very uplifting. So at the very end of the PV, it shows a rather gruesome clip of a horse giving birth to a foal.
In the beginning of the book, Eiko is singing the Amagi Brilliant Park theme song in a recording studio. Macaron thinks that she's a good singer, but notes that she feels stifled, like she's always holding something back. Why she's singing is revealed in a flashback: in order to convince Shiina to sing, Biino and Eiko suggested to Seiya that they be allowed to be with her while she's singing. However, Seiya mistakes their suggestion for volunteering to form a girl group with Shiina. Though they try to protest, Seiya immediately announces the group's formation and they are named "Task Force ABC" per Moffle's suggestion, who originally suggested it as a joke. Once Eiko finishes singing, her, Biino, and Shiina are invited to eat by Macaron in celebration of getting his daughter to visit. They go to a pub and Macaron gets drunk and starts rambling nonsesically about music, much to the girls' consternation. At this point, a man come in and tells Eiko he was looking everywhere for her. He then tells her to leave, and when she tries to refuse he tries dragging her out. Macaron tries to get him to stop peacefully, but when the man just brushes him off, he quickly becomes violent. He intimidates the man and almost attacks him, but Eiko stops him before he can. She tells the man to leave and that she will apologize for her behavior. After he does, she apologizes and says that she will scold him later, before revealing that man, Shuichi, is actually her fiance.
Later, Eiko goes to Seiya's office to tell him and Isuzu about her circumstances. She reveals that her family runs Amagi Hospital, one of the biggest hospitals in the entire reigon, and that she is that daughter of it's director, Eizo Adachi. She tells them that Eizo is very angry at Amagi Brilliant Park due to Macaron threatening her fiance, and that he wishes for her to quit her job and to force Amaburi to make reparations for thair employee. Saiya asks if her father wants to have Macaron fired, which Eiko confirms and states that she finds it unacceptable as it was all her fiance's fault. She looks rather loathful towards Shuichi, making Seiya realize that she probably didn't like him very much. She then apologizes as she sees most of it as her own fault, and Seiya tells her not to worry. When Seiya asks her if she'll help dig up blackmail on her father, she agrees, but warns him that her father's anger might not be so easily pacified. Seiya asks her why, and she tearfully tells him that in an argument with her father, she told him she was in a relationship with a superior at work in the heat of the moment, and that she wanted him to call of the engagement. Believing it to be himself, Seiya asks her who she said she was in a relationship with, and she says she told her father she was seeing Macaron, much to Seiya's shock.
When Seiya, Isuzu, and Moffle explain the situation to Macaron, Isuzu tells him that Eiko was very ashamed of what she did, and that the only reason she wasn't here was because she was too ashamed to face him.
On the day Eizo is supposed to arrive, Eiko bumps into Macaron and apologizes sincerely to him. She tells him that she won't let him be fired no matter what, going as far as to say that if it comes down to it, she'll kill her father, then take her own life. Then she reveals she had already tried to tell her father she had lied, but he'd thought she was trying to protect Macaron and hadn't believed her. Melancholy, she expresses her disappointment that her father could be so cruel. Macaron tries to reassure her, but fails to cheer her up. After that, she follows Moffle and Tiramy as they drag Macaron to Room B-3, where everyone else and the Iron Phore, a device made for transforming magical beings into humans, are waiting. After Macaron is stuffed inside and starts screaming in pain, Eiko worriedly remarks that it seemed a bit cruel. Moffle, tells her that he can handle it, but she nonetheless remains worried about him. When he comes out of the machine, Eiko is stunned by his handsomeness, first acting disbelieving, then shy.
While Macaron is showing her father around, Eiko stays with Rarapā, Macaron's daughter. When Macaron comes to see Rarapā, she's in a kiosk with Eiko, playing with a Moffle mask. A short while later, when Macaron tells Rarapā he has to leave for a bit and Rarapā tells him that she's fine with staying with Eiko. Eiko follows up by apologizing to Macaron and telling him she'll keep her safe. Rarapā tells her she doesn't have to bow to him, calling him an "old geezer", and while Eiko tries to protest, Rarapā tells her it's fine. Later, Eiko and Rarapā ride the Thrill Coaster: Blackout, and Rarapā remarks that it was fun to Eiko. When Macaron comes back, Rarapā once again acts distant, and though Eiko is worried, she stays out of it as not to intrude in a family matter. After he leaves and comes back another time, Eiko emails him their location in Splash Mountain. Upon seeing him, Rarapā tells Macaron he can just focus on his work and leaves. Eiko tells Macaron she'll handle it and follows after her. She stops Rarapā and manages to convince her to go to Macaron's Music Theater and watch him perform. After Macaron gets off the Ferris Wheel with her father, she apologizes to Macaron, who advises her to speak with her father. Before he can leave, Eiko tells him he still has a performance to do at his Music Theater and says she'll explain everything there. After Macaron performs, he sees Rarapā in the audience and she tells him what Eiko did.
The next day, Seiya comes to see Macaron, Tiramy, and Moffle and tells them that while her father had called off the engagement, Eiko still plans to quit in order to atone. While they're discussing a way to replace her on Taskforce ABC, Isuzu comes in and tells them that it won't be necessary. Eiko comes into the room and reveals that while she wanted to take some time off as a way of atoning, Isuzu convinced her to stay. Eiko finishes by bowing and asking them to work with her, and when Macaron asks if he can count on her, she happily agrees.
Amagi Brilliant Park Episode 6: She applied for a position at Amagi Brilliant Park, and her appearance surprised Isuzu, who previously saw her in a dream, as well Seiya and Moffle as she wasn't eccentric, but normal. She reveals her previous occupation in A.V films, which surprises them as she tells them while she was satisfied with her old job, but wanted something where she would be able to see the smiles on the customer's face personally. With that she is hired. Thinking that she meant AV as in Adult Video, Moffle looked up what he thought was her and was put off by it.
Amagi Brilliant Park Episode 7: She works at the pool, acting as a narrator and translator for the fairies at the play before the pool comes under attack by Tetsuhige and his crew. Despite being captured, Eiko remained calm because the visitors were enjoying themselves. Curiously, she showed that she is capable of understanding what the seal crew were saying, despite them not being mascots. After the park was liberated, Eiko was pleased with this and kept the visitors in good spirits.
- The name Eiko means "projection" (映) (ei) and "child" (子) (ko).
- Eiko's surname Adachi means "peace, quiet" (安) (ada) and "accomplished, reach, arrive, attain" (達) (chi).
- Eiko share the same Voice Actress as that of Jin Russell of 'Mondaiji-tachi ga Isekai kara Kuru Sou Desu yo?.
- Eiko is capable of understanding what the mascots are saying when they are not speaking.
- Shoji Gatoh (the author) had an interview when he said that Eiko was really an Animal Video she is the number 10.
|V • T • E Characters of "Amagi Brilliant Park" Universe|
|Main||Seiya Kanie • Isuzu Sento • Latifa Fleuranza|
|Casts||Mascots||Moffle • Macaron • Tiramy • Wanipee • Dornell • Jaw|
|Fairies||Muse • Salama • Sylphy • Kobory|
|Others||Triken • Ashe • Wrench-kun • Okuro • Nick • Genjūrō • Rubrum • Taramo • Eiko Adachi • Biino Bandō • Shiina Chūjō • Tetsuhige • Cameo (Chief of General Affairs • Codain • Future • Jack Randy • Mer-chan)|
|Others||Takaya Kurisu • Aisu Kyūbu • Takami • Mutsumi Terano • Kanae Tsuchida • Kimura • Rude Guests • Light Novel (Saki Kyūbu)|