Luka Urushibara

Luka Urushibara (漆原るか) is a close friend of Mayuri Shiina and so-called protégé of Rintarou Okabe. While feminine in appearance and personality, Luka is a male in most world lines. Mayuri Shiina is his classmate, who often attempts to coerce him into cosplaying (without much success).

Appearance & Personality
Although being biologically male, Luka has an extremely feminine appearance, causing him much trouble (and attention) from men (even Daru was at one point attracted to Luka's appearance). He is very slim, with thin arms and lanky body.

Luka had always dreamed of being a complete girl, and was disappointed that he was born a male. This changes later on in the story, as Luka was turned into a female through the influence of a D-mail.

He is very sensitive and emotional, as simple sudden responses from Rintarou can cause him to cry or tremble. He likes to wear girly clothing, which caused Kurisu to confuse him for a real girl when the two met in Rintarou's lab. Rintarou even described him as "more girly than any girl, more feminine than any female" in the game.

Luka harbors deep feelings for Rintarou, ever since their first encounter in Akihabara, when he was still a male. However, Luka felt these feelings were taboo and kept them hidden. Later in the story, as Rintarou attempts to save Mayuri by reversing the effects of sent D-mails, the female Luka tearfully agreed under the condition of Rintarou taking her out on a date. The date turned out awkwardly, since Rintarou was unable to be himself around her. He came to see her at the shrine and apologizes for botching the date, and the two embrace. Luka said she would still love him even if she's no longer female.

Plot
Luka was first introduced as an extremely feminine individual. Okabe expressed his own confusion over this matter quite a few times throughout the game, and at the near beginning of the anime.

After learning of the existence of SERN and the IBN 5100 personal computer, Rintarou discovered the computer being stored at Luka's family's shrine. However, later in the story in the worldlines where Luka has been changed to being female, Luka accidentally broke it when she was cleaning the storehouse on Jan. 4, 2009.

Being told of Rintarou's experiments, Luka tells the Future Gadget Lab members a Japanese urban legend: if a pregnant woman eats more meat during her pregnancy, then her baby will be a boy, and if she eats more vegetables, her baby will be a girl. The Future Gadget Lab, although skeptical of whether or not the urban legend is true, lets Luka send a D-mail back to his pregnant mother's pager, telling her to eat more vegetables. In episode 10, it's revealed that the D-mail has worked and the characters are transferred to a world line where Luka was born a girl. This causes an extremely awkward situation in which Okabe does not realize this and gropes Luka's crotch in order to prove to the Future Gadget Lab that she is male. He quickly learns that he's been moved to a world line where Luka is a girl and that he's been accidentally sexually harassing her while causing Luka heavy embarrassment.

Later, when Rintarou attempts to achieve 1% divergence, he was troubled by the thought of reversing Luka's wish. Luka agreed to it, though reluctantly, after confessing her love for him and requests that he takes her out on a date. The date turned out awkwardly, since Rintarou was unable to be himself around her. He came to see her at the shrine and apologizes for botching the date, and the two embrace. Luka then spends the rest of the day practicing with the sword Samidare along with Rintarou; both of them feeling genuinely comfortable in each other's company.

Luka, who still remembered her first meeting when Rintarou saved Luka from being harrassed on the street, even though this memory is from a world line where she was born male, revealed to Rintarou that she had been in love with him since that first encounter that she shouldn't be able to remember, and that she will still love him no matter what happens, female or not. Rintarou smiles and sends the D-mail, reverting Luka back to being a male.

Luka's Ending in the Game
In this route of the visual novel, Rintarou decides in the end to not send the D-mail that would make Luka return to being a boy again. He convinces himself that Mayuri will still die no matter what he does and he doesn't want to sacrifice Luka's happiness.

This ending starts by Luka confessing to Rintarou and swearing to give him her mother's pager number on the condition that the two go on a date together once. The two's date is deeply awkward and contrived, so much that Luka cuts it off abruptly, leaving Rintarou to guilt over it. He realizes that it wasn't truly a date because he was trying too hard to impress her by not being himself, and rushes over to the shrine where the two spend genuine bonding time together. After which, Luka gives Rintarou her mother's pager number in order to send another D-mail to Luka's pregnant mother. This will cause Luka's mother to believe that the first D-mail she received -the one sent by Luka in order to turn into a girl- was spam, ignore it, and continuing on eating more meat, thus giving birth to a male Luka. Because Rintarou doesn't want to turn Luka back into a boy, stating that he does not want to wipe out any memories anymore, the timeline goes on and Mayuri still dies.

Realizing the devastation she has wrought, Luka feels guilty about Mayuri's death. Remembering that Mayuri wanted Luka to cosplay in the next convention, Luka with the help of Rintarou, leaps back in time to give Mayuri at least some happiness. The plan was a success, as in that world line Luka, Mayuri and Rintarou went to the convention together but left Mayuri's fate ultimately unchanged. The scene closes with Luka producing the pictures they took together with Mayuri at the convention and with Rintarou at peace now that he has given Mayuri some happiness. After the credits, Rintarou is shown to have fathered a child with Luka.

Quotes

 * "If I go back to becoming a guy, I'm going to forget all about today, that the two of us went on a date, that the two of us trained, that I was able to touch you this way...If I knew I had to suffer like this, I would never have wished to become a girl..."

Trivia

 * Though being feminine, Luka always uses the term "boku" to address him/herself. "Boku" is a male form of addressing oneself in Japanese, so it is unusual that a person like Luka would use it in the world lines where she is biologically female.
 * Luka has an older sister in college who, according to Luka, is the polar opposite (in terms of gender attraction) of him. Though she is only mentioned in the game.
 * Okabe's nickname for Luka regardless of gender is "Lukako" (Anime: "Rukako") "-ko" is typical ender of many female given names in Japanese.
 * Luka's ending is the only outcome of the game in that Mayuri's death is definite, as Rintarou gave up on his attempts and decides to make Mayuri happy one last time instead. Mayuri also dies of natural causes (heart attack) in this ending.
 * Lab Member 006. Joined at episode 8 of the anime (chapter 4 in the visual novel). He is recruited by Okabe because he wanted to make a D-Mail to become a girl.