Naoko Izumi is a minor supporting character in the manga and anime series Great Teacher Onizuka. She is a student at Holy Forest Academy and a member of the group led by Anko Uehara, alongside Mayuko Asano. Izumi is known for her tendency to fall asleep easily and deeply, a trait that Onizuka himself comments on. She is also noted for having a large bust, which Onizuka points out in a characteristic crude remark. In terms of personality, she is generally quiet and follows the lead of Uehara, but she does not display any particularly strong motivations or goals of her own within the story. Her role is largely as a background figure within Uehara's clique, and she does not play a major part in any of the series' central conflicts. Izumi's key relationship is with Anko Uehara, as she is a loyal follower of her group. She has no romantic interests depicted in either the manga or the anime. Her development occurs when, after Onizuka helps resolve Uehara's personal issues during the Okinawa field trip, Izumi along with Uehara and Asano become members of the Onizuka-clan in volume 13 of the manga, signifying a shift in their allegiance from antagonistic to supportive of Onizuka. Izumi does not possess any notable abilities or skills beyond being an ordinary student. She does not appear in any of the live-action drama adaptations of the series.