Mayuri Shiina

Mayuri Shiina (椎名 まゆり, Shiina Mayuri), also known as Mayushii☆, is Rintaro Okabe's childhood friend, a part-time worker at MayQueen+Nyan² and a member of the Future Gadget Lab. She is a fan of cute things, like the Upas from the in-universe RaiNet Kakeru series, an avid cosplay maker and a friend of Luka Urushibara and Faris NyanNyan.

During the year 2032 in the Beta Attractor Field, Mayuri becomes Kagari Shiina's adoptive mother.

Appearance
Mayuri is a short girl with short, black hair that forms fringes that sweep from either side, light-blue eyes and noticeably thick eyebrows.

Mayuri's outfit is simple and comfortable, consisting of a light blue one-piece dress and a hat of the same color. She also wears black leggings underneath her clothing.

Her clothing for the colder seasons consists of a white, long-sleeved dress with a long, blue skirt tied together by a thick, pink ribbon at the waist. She also wears black leggings and white boots. Outside, she additionally wears a white-pink hat and a big, pink scarf.

When she attends to her work at MayQueen+Nyan², she wears a blonde wig tied into a long ponytail.

Personality
Mayuri possesses an extremely childish and naïve attitude for her age. While this may have something to do with her inability to accept the death of her grandmother when she was young, Okabe states at one point that she has always been a little bit different, though he never goes into any detail beyond this. Mayuri has a great fondness for cute things like Upas, and likes to give cute nicknames to familiar people, like Okarin for Okabe, being a portmanteau of his last and first names Okabe Rintaro, even referring to herself as Mayushii, being a portmanteau of Mayuri Shiina.

She also has a moral compass and becomes anxious and unhappy whenever Okabe does something "bad", such as hacking into SERN's files, although she does not do much beyond chiding him for it. She often seems to forget about it after a while or when the conversation topic changes, and rarely holds grudges.

Though appearing as one of the less intelligent members of the lab, according to Okabe, Mayuri is very perceptive, often being surprisingly quick to catch things no one else notices, and being good at understanding how others feel. Kurisu Makise comments on this, stating that while everyone else was concerned with the PhoneWave (name subject to change), Mayuri continued to take matters to her heart. This is shown when she was the one who managed to figure out that Daru was Suzuha's father before anyone else. Mayuri also does not question Daru's perverted comments and mannerisms much, or is not in any way offended by them.

Despite her apparent ditziness, Mayuri is distinctly aware of the fact that she is the least intelligent member of her group and struggles with a feeling of uselessness. According to Suzuha, the Mayuri in the future would frequently comment on her own uselessness with a depressed expression. In Steins;Gate 0, upon learning the truth about why Okabe chose the Beta Attractor Field, she feels as though Kurisu had more of a right to live then her as she was much more useful.

Despite her quirkiness, she is also responsible for Okabe's well-being, usually tending to his needs in a mutual bout of gratitude. In Steins;Gate 0, Mayuri shows great concern for Okabe's well being after Kurisu's death. Near the end of the game, she confesses that she has more than deep platonic feelings, proclaiming her love for Okabe to be superior to Kurisu's, yet wanting him to be happy with Kurisu even if it meant her death.

Background
As a child, Mayuri was close friends with Rintaro Okabe and they could often be seen together. As Mayuri's parents work a lot, she was mostly brought up by her grandmother. However, after the death of her grandmother when Mayuri was 11, she entered a state of depression that caused her to be unable to talk to others, and could be seen in front of her grandmother's grave in the cemetery most of the time.

Out of fear that something could happen to her, Okabe tried to call out to her while when she was in the cemetery. One day six months after, as Mayuri raised her hand towards the sky after it stopped raining, Okabe's fear reached its limit, and he rushed to hug her, proclaiming to be a "mad scientist" and that Mayuri was his "hostage", and that, therefore, she was not allowed to go away. Fortunately, the new persona he created helped her overcome her immense grief and she went back to normal, as she was "forced" to stay.

Mayuri started becoming interested in sewing cosplay outfits when Okabe asked her for a costume of Kyoujiro, the flame user from King of Histories. At the time, she thought the outfit suited him. Sometime, at an event, Mayuri met Fubuki and Kaede and they became cosplay friends. Mayuri often sews cosplay outfits for them, having little interest in wearing them herself.

About two weeks after Okabe established the Future Gadget Lab, Mayuri began showing up regularly, leading Okabe to officially dub her as Lab Mem 002. At some point, she started working at MayQueen+Nyan² as a waitress.

Quotes

 * “Tutturu~!” — Mayuri greeting someone, and her catchphrase.
 * “But isn't doing this bad? Mayushii doesn't want you to do bad things...” — To Rintaro Okabe.
 * “We should work towards world peace. Like giving everyone an Upa cushion...” — Mayuri's D-Mail wish.
 * “You're shining Okarin. [...] You're shining. Chris-chan too. Like two bright stars in the sky. [...] Since Chris-chan became a lab mem, it feels like things have really started to happen, like we're a real lab, you know? [...] Chris-chan is really a big help to you, I know... But I can't do anything to help... I wish I were smart too... then maybe I could help.” — Mayuri expressing her feelings to Okabe.
 * “Just look, we've made so many friends... There's Daru-kun, Chris-chan, Luka-chan, Suzu-san, Moeka-san, Feris-chan, Braun-san, Nae-chan and more! In the spring you seemed so lonely... But now you're fine. You don't need Mayushii to be your hostage anymore.” — To Okabe.
 * “Finally... Mayushii was... useful... to Okarin.” — Mayuri after protecting Okabe from being hit by a Rounder's car.
 * “The whole time you and Chris-chan were hurting... While Mayushii was making costumes... like nothing was wrong... I feel so stupid! I didn't know anything! I need to see Chris-chan!” — To Okabe after knowing what he and Kurisu Makise have been through.
 * “Hum, I don't know who it was but Mayushii feels like she had a very important friend. And whenever I think about that important friend, my heart hurts, like hnng, you know? And sometimes, I hear a voice. That voice tells me to 'find happiness'. I wonder if that person is the reason of why Mayushii is with Okarin now... If I ever meet this person again, I want to tell them thanks.” — Mayuri talking about Kurisu in her ending.

Trivia

 * Mayuri's voice was used as a user guide for the PhoneWave (name subject to change). According to Rintaro Okabe, it made the PhoneWave sound silly.
 * According to Okabe, his first kiss was with Mayuri in elementary school, although they were "just messing around".
 * Mayuri is bad at cooking.
 * In Steins;Gate 0, it is showed that after taking cooking lessons from Yuki, her skill has improved significantly.
 * Mayuri lives in Ikebukuro.

Etymology

 * Mayuri's surname Shiina means “chinquapin, mallet, spine” (椎, shii) and “name, noted, distinguished, reputation” (名, na).