Ringo Oginome is a key character in the anime series Mawaru Penguindrum. She is a seemingly eccentric high school girl with an obsessive crush on her teacher, Keiju Tabuki. Ringo believes that by fulfilling the events written in her deceased sister Momoka's diary, she can bring her sister back to life. Her actions are driven by a deep sense of loss and guilt, making her a complex figure whose journey is central to the unfolding narrative. Ringo's character evolves, revealing her vulnerabilities and ultimately seeking redemption through love and sacrifice.