[Zero Tanuki] Oyako no Fudeoroshi (Amaenbo ~Uchi no Mama, Pheremone ga Peak de Hanshokuki~) [MrBubbles]

On his birthday, young Mikado is brought to a retreat apart from the main Yamato household, where his curvaceous mother Tokiwa unveils the family's secret coming-of-age ritual—a rite passed down through generations and consummated with the mother's own body. She smothers her nervous son against her enormous breasts, nursing him as she once did as an infant, before mounting him and riding him through overwhelming rounds that leave both drenched, her maternal instincts and raw lust fusing into one insatiable hunger. Just when Mikado thinks it's over, Tokiwa gleefully reveals the truth: the ceremony lasts ten days of nonstop baby-making, and once it's complete she promises to give birth to his child.