In an alternate Edo-era Japan, breast size determines a woman's wealth and social standing, and the Manyuu Clan controls the secret techniques for enlarging them. Chifusa Manyuu is groomed as the clan's next head, but she rebels against the cruelty her family inflicts to maintain that power, stealing the clan's forbidden scroll and fleeing into hiding. On the run, she sets out to dismantle the twisted hierarchy the Manyuu Clan built its fortune on.