Mayu Hoshino is a character from the anime television special Saint Elmo - Hikari no Raihousha. She is closely connected to the protagonist, Issei Yuuki, as his girlfriend. Her background involves a previous space mission to the solar power plant Saint Elmo, during which an incident leaves her severely injured. Following that incident, she is hospitalized and remains in a coma. Her condition becomes a central source of narrative tension when the Saint Elmo plant begins to malfunction, causing Earth to lose its primary energy supply. The resulting power crisis jeopardizes the hospital equipment that sustains her life, making her survival dependent on a swift resolution to the plant's problems. Her role in the story is primarily that of an emotional anchor and motivator for Issei Yuuki. Her critical state drives his determination to join the team of technicians sent to Mercury to repair the facility. The urgency to save her life adds personal stakes to the broader mission of restoring power to Earth. In terms of personality, the available information suggests that she is a figure of warmth and care, someone for whom the protagonist feels deep concern. Her relationship with Issei Yuuki underscores the personal cost of the crisis and highlights the human element within the large-scale technological emergency. While her own development is limited due to her comatose state for much of the story, her presence shapes the emotional journey of the main character. No notable abilities or special skills are recorded for her; her significance lies in her personal connection to the protagonist and the role she plays as a catalyst for his actions.