Luka Urushibara, a close companion of Mayuri Shiina and Rintaro Okabe, presents a striking contrast between biological maleness and a delicate, traditionally feminine appearance. Raised under familial pressure to adopt feminine roles, Luka wore women’s attire and served as a shrine maiden at Yanabayashi Shrine from childhood through adolescence, fostering persistent struggles with self-image despite an inherent knack for cooking and domestic skills. A turning point arises when Okabe defends Luka from harassment in Akihabara, mistook for a female cosplayer. This sparks Luka’s concealed romantic attachment to Okabe, who later gifts the toy sword Samidare, mentoring him in swordsmanship and forging a bond of trust. The Future Gadget Lab’s time experiments entangle Luka in paradox when a D-Mail alters his birth gender by influencing his mother’s diet. Temporarily female in a shifted worldline, Luka faces emotional distress after Okabe unknowingly crosses boundaries, exposing the fragility of identity across timelines. Though the D-Mail’s reversal restores his original form, residual memories of the alternate reality drive a heartfelt shrine confession, affirming love transcending gender. A non-canon narrative branch explores an unchosen path: Okabe retains the female worldline, where Mayuri’s eventual natural death leads Luka and Okabe to revisit the past, honoring her final wish. Their child emerges in this divergent timeline, excluded from the canonical Steins Gate outcome. In later events, Luka supports Okabe through emotional crises and global threats. One timeline witnesses his mortal injury during a clash with adversaries, his final moments marked by relief at Okabe’s renewed determination—a catalyst for timeline reversal. Luka’s journey navigates loyalty, concealed affection, and societal gender expectations. Official sources underscore his male self-identification across most realities, with feminine traits stemming from external pressures rather than innate identity. The pronoun *boku* and shrine obligations reflect a persistent, if uneasy, adherence to male roles. Interactions, such as Kurisu Makise’s initial misgendering, provoke dialogues on perception versus selfhood, framing Luka as a lens through which norms of authenticity are questioned.