Shirasagi Yumiko arrives as a transfer student at Jusho High School, initially appearing ordinary until her curiosity about classmate Akemi Nakajima's unusual behavior draws her into supernatural events. Witnessing the demon Loki assault teacher Miss Ohara in the computer lab traumatizes her. Despite Nakajima's warnings that Loki targets her, she returns to school and is captured, enduring physical violation by Loki. Her latent divine powers manifest under the goddess Izanami's guidance during the escape attempt. Loki fatally wounds her, but she directs Nakajima to take her body to Izanami's tomb in Asuka for resurrection, revealing herself as Izanami's reincarnation—the "Megami Tensei" (Goddess Reborn) from whom the series derives its name. Resurrected, she remains in Yomi, the underworld, training with Izanami to master her powers. Returning to the human world, she confronts Ohara—now empowered by carrying Loki's child—who killed Yumiko's family in retaliation for Loki's demise. During a battle at Nakajima's residence, Yumiko kills Nakajima's mother while she is possessed by a demon, an act that haunts her. She later pursues Ohara into Soga Forest and eliminates her. The demon Seth possesses Ohara's unborn child and attaches to Yumiko, using her body's magnetite to merge the human and demon realms. Crucified within Seth's flesh tower, she endures torture that destroys her eyesight. Nakajima attempts to free her during a plan to banish Seth to space, but she remains trapped until they coordinate a final attack that destroys Seth. Demons cling to her during the collapse. Though she urges Nakajima to let her fall into the demon realm to seal the dimensional rift, he rescues her, leaving the gateway open. Blind and facially scarred in the aftermath, Yumiko and Nakajima suffer nightly demonic possession, straining their relationship. A message purportedly from Izanami calls them to Asuka, where they encounter hostility, leading to Nakajima's violent outburst and arrest. During the chaos of his execution, Izanami's voice reaches Yumiko, explaining Lucifer suppressed her power. Restored to full strength and physical form, she approaches Nakajima, but he—consumed by madness—attacks her. Izanami seizes control of Yumiko's body and kills Nakajima. Devastated, Yumiko takes her own life with his sword. Izanami subsequently inhabits Yumiko's resurrected body to bury Nakajima. In the video game continuity, her arc diverges significantly. She accompanies Nakajima to defeat Lucifer, who revived Loki and imprisoned Izanami. Together, they navigate a labyrinthine dungeon, liberate Izanami, defeat Lucifer's generals, and triumph over Lucifer himself. This narrative omits the novels' tragic elements, depicting her as a steadfast ally without the physical deterioration or suicide. Her character design varies across media: the OVA features a black blazer, white shirt, red ribbon, and long skirt; the manga depicts a sailor-style uniform with a blue skirt and tights; game artwork often shows long black hair and brown eyes, though some covers depict red hair. In gameplay, she functions as a magic-oriented deuteragonist, learning skills like healing (Medi), status recovery (Patch), and fire attacks (Bottorra) based on party intelligence and level. Her name, "Shirasagi," means "white heron," and "Yumiko" translates to "bow child."