Ikumi was the mother of Takuma, Shohei, Toshiyuki, and Tsukasa. She and her husband, Yutaka, were tragically killed due to a conspiracy masterminded by Hizaki. As a member of the GRAVE Division, Ikumi instilled a strong sense of justice in Tsukasa, aiming to protect her from becoming a victim of violence against women. Interestingly, young Tsukasa also picked up some "bad words" from Ikumi, repeating them without understanding their meanings.
Although Ikumi was biologically the mother of only Takuma, Shohei, and Toshiyuki, she and Yutaka shared a close friendship with Wakasa. They agreed to adopt Wakasa's daughter, Tsukasa, should anything happen to her. Even after discovering the truth about her biological parents, Tsukasa continued to regard Ikumi as her true mother. In a message left on a memory disk hidden within Tsukasa's protector, Ikumi encourages her to follow her sense of justice throughout life.










