Mayuri Shiina

Mayuri is cheerful, gentle and accepting. She has little interest in challenging Okabe's eccentric behavior and instead treats Hououin Kyouma as another familiar part of her childhood friend's personality.

She dislikes arguments and becomes uncomfortable when the laboratory's members fight. Although she cannot always follow their scientific discussions, she often notices emotional problems that the more analytical characters overlook.

Mayuri loves cosplay and cute merchandise, particularly Upa goods. Her habit of reaching toward the sky—the Stardust Handshake—comes from childhood memories of watching the stars with her grandmother.

Mayuri has no supernatural powers or advanced scientific expertise. Her practical talents center on sewing and costume-making, and she creates cosplay outfits with considerable skill.

Her importance to the Future Gadget Laboratory is primarily social rather than technical. Mayuri keeps its members connected as friends instead of allowing the group to become purely an experimental project.

In later Beta-world-line events, Mayuri becomes capable of making decisions with enormous consequences for the timeline. Her understanding of Okabe ultimately helps restore his determination when scientific arguments alone cannot reach him.

Mayuri is one of the three original members of the Future Gadget Laboratory and is present as Okabe and Daru's harmless gadget-making club becomes involved with genuine time travel. She welcomes Kurisu Makise and the laboratory's later members without sharing Okabe's suspicion of newcomers.

Her importance changes dramatically once the consequences of D-Mail experimentation become clear. In the Alpha attractor field, convergence repeatedly causes Mayuri to die regardless of Okabe's attempts to save her. Those repeated deaths drive him to use the Time Leap Machine again and again while searching for an escape.

Reaching the Beta attractor field saves Mayuri but leads to a different future. In Steins;Gate 0, Mayuri eventually recognizes how much Okabe's failure to save Kurisu has changed him and travels into the past with Suzuha to ensure that her earlier self gives Okabe the encouragement he needs to try again.

Rintarou Okabe is Mayuri's childhood friend and emotional anchor. After her grandmother's death, Okabe declares her his "hostage" as part of an effort to keep her connected to the world around her.

Itaru Hashida is Mayuri's fellow founding Lab Member and friend, with whom she shares interests in anime, games and otaku culture.

Kurisu Makise becomes Mayuri's close friend after joining the laboratory. Mayuri is particularly perceptive about the growing attachment between Kurisu and Okabe.

Suzuha Amane becomes increasingly important to Mayuri in the Beta world line as they work toward changing the future.

Kagari Shiina is a war orphan whom the future Mayuri adopts as her daughter in 2036.