Mrs. Tōjō serves as the stepmother of Iori Tōjō, the adopted heir to a prosperous family enterprise. She devises a scheme to eliminate Iori prior to his father's death, aiming to seize control of the family's assets and business operations. To execute this plot, she employs the Green Ship organization—a group that publicly operates as a stunt training school while secretly functioning as an assassin training camp. Her actions trigger the narrative's central conflict by contracting Green Ship's leader, Kazusa Himuro, to assassinate Iori. This compels Tomoe Oujima, a former Green Ship member who uncovers the organization's lethal true purpose, to intervene and protect Iori from the attempt. Mrs. Tōjō's motivations arise from her intent to prevent Iori's inheritance and secure uncontested command of the family establishment.