In a future Japan struggling with overpopulation, a notorious figure named Junta Monamari is identified as the root cause due to his prolific womanizing as the 'Mega-Playboy.' To rectify this crisis, Karin Aoi, a skilled 'DNA Operator,' is tasked with journeying back in time to modify Junta's genetic makeup and thwart his Mega-Playboy destiny. Armed with a special bullet known as DCM, Karin aims to suppress Junta's troublesome DNA, ensuring a hefty reward that could fulfill all her aspirations. As Karin faces the moral dilemma of altering fate, she finds herself torn between her mission, her growing affection for Junta, and the unrequited love of Ami, a long-time admirer of Junta. The question looms: will Junta succumb to his womanizing instincts, or will Karin's intervention reshape the future of Japan and the lives intertwined in this complex tale?