Mai Sakakibara's fiancé Youji perished in a mountain climbing accident. Resolute in bearing his child, she sought help from his genetic research colleagues. The endeavor demanded significant funding. To secure resources, she became a DNA Hunter—a role requiring procurement of semen samples for women seeking offspring from designated men, employing all necessary methods. Her initiation test mandated successfully extracting a sample from an unknown individual. She pursued multiple targets through physical intimacy to gather genetic material. This occupation financed somatic cell research to conceive Youji's child. A conspiracy eventually surfaced, linked to the project.