Sagiri Izumi, a 12-year-old silver-haired middle school student with piercing blue eyes, stands at 139 cm (later 148.5 cm) and weighs 46 kg. Born December 10 with blood type A, her petite frame conceals a complex duality: a reclusive hikikomori confined to her room after her mother’s death, and "Eromanga Sensei," a masked illustrator producing erotic art for light novels, including those penned by her stepbrother, Masamune Izumi, who delivers meals to her door. Trained by her mother, she began illustrating Masamune’s novels at nine but withdrew socially after her mother’s passing. Livestreaming reignited her passion, prompting her to adopt a male persona using a voice changer and mask. Her art fixates on firsthand observations of female figures in swimsuits or underwear, favoring slender, flat-chested forms mirroring her own. Though averse to violent scenes—a hurdle she later confronts—her technical skill thrives. Initially communicating with Masamune via floor stomps, her guarded world cracks when he uncovers her identity. Reluctant to embrace their sibling bond, she bristles with jealousy toward girls like Elf Yamada, yet gradually ventures beyond her room, forming uneasy alliances with rivals Elf and Muramasa Senju. Collaborations blur professional and personal lines as she balances isolation with connection. Shy yet defiant online, she hides behind her pseudonym, attributing it humorously to "Eromanga Island" on a blog few believe. Her evolution sees her competing at the Light Novel Tenkaichi Butōkai, confronting societal norms to voice feelings for Masamune, and aspiring to co-create an anime. Subtle nods to naval history echo in her name’s origin from a Japanese destroyer, while her family’s swordsmith legacy lingers unspoken yet intrinsic to her disciplined craft.