Manyu Scroll

In a world in which having large breasts means everything, the successor of the powerful Manyu family, Chifusa Manyu, defects and steals the Manyu Scroll of Secrets (which contains all the Manyu secret techniques for breast enlargement), but is wounded during her escape. She is found by a woman who was recently attacked by Kagefusa, a Manyu assassin and Chifusas sister, resulting in her breasts becoming small and effectively making her poor. The woman becomes jealous of Chifusa and attempts to sever her breasts in a fit of rage, but Chifusa manages to calm her down. As Chifusa is about to leave, she is confronted by Kagefusa, who had also captured Chifusas comrade, Kaede, and severed her breasts. As Chifusa stands against Kagefusa, she uses a special technique which steals Kagefusas breasts and adds them to her own. As Kagefusa is forced to retreat, Kaede decides to join Chifusa on her journey.

Having not eaten for days, Chifusa and Kaede get a job at a maid bar, but soon get fired due to Chifusas short temper around the rowdy customers. Collapsing due to hunger, they are rescued by a man whose daughter was stricken by a mysterious breast disappearance. The man asks Chifusa to take his daughters place in a contest against a neighboring village to please Hatomune Mie, a rowdy landlord. The opposing team sends a Manyu assassin to attack Chifusa, but she manages to beat him and wins the contest the next morning. Although Hatomune later hears word about Chifusas true identity, he allows her to go, having been mesmerized by her breasts. After she leaves, Hatomune vows to find Chifusa again and get to touch her breasts.

Chifusa and Kaede save a woman called Osuzu from four "monsters" that assaulted her and tried to molest her breasts. At Osuzus village, both heroines meet a man named Yasuke, who lost his massively-breasted wife two years prior and struggles with different jobs to maintain his four kids, and whom Osuzu is hopelessly in love with. In order to help Osuzu, Chifusa and Kaede convince Osuzus grandfather to organize a hunt for the monsters, leaving Yasuke to take care of Osuzu; ultimately Osuzu manages to charm Yasuke and they begin dating. During the hunt, Chifusa and Kaede stumble upon the monsters and after a brief fight they discover that they were just Yasukes four children, who played with their captured womens breasts because they missed their deceased mothers bosom. Chifusa strikes a deal with them and makes them promise not to assault any more women...after she lets them play with her own breasts for an entire afternoon.

Chifusa and Kaede stop at a village so Chifusa can get a massage to ease the pain caused by her heavy tits. The masseus, a girl named Momoha, tells them of "The Boobie Kid" a local thief that steals rich womens tits and allegedly gives them to the poor. Suspecting that this Boobie Kid might be a Manyu who knows how to master the Chichinagare technique, Chifusa takes a job as a bodyguard for a local big-breasted woman who will likely be the next target in order to catch the Boobie Kid. At the same time, the big-breasted landlady also employs another girl called Ouka as a bodyguard and immediately Chifusa becomes suspicious of Ouka because of her unusually good swordsmanship. That night, the Boobie Kid strikes but is chased away and caught by Chifusa. The Boobie Kid is later revealed to be Momoha, the masseus, and that she is a member of the Munamori family and that she knows a technique similar to the Chichinagare that Chifusa cannot use.

While traveling through the forest, Kaede and Chifusa save a painter called Sakuji Itamune from a trio of Manyu guards who wanted to kill him because of the content of his art. When Sakuji sees Kaede, he immediately asks her to model for his next painting. When Chifusa tells Kaede she shouldnt because it would slow down their progress, Kaede mistakes Chifusas motivation and believes she doesnt want her to model because she is jealous, prompting her to abandon Chifusa. When they are about to start painting, Sakuji reveals he is a nude painter who only paints flat-chested models (which is why the three Manyu guards had attacked him) which shocks Kaede and makes her escape; though as soon as she leaves she is attacked by the three Manyu guards whom they had run into earlier.

Chifusa and Kaede arrive to the Munemori village, hometown to Chifusas mother, which is now in ruin. There they reunite with Chifusas grandmother and Chifusas aunt, Tsuhuya Munemori, and her baby daughter, Hazuki. Tsuhuya agrees to teach Chifusa how to master the Breast Flow technique. At the same time, Kagefusa and Kokage take Ouka to Edo village, where they have a day of fun and a night of drinking, during which Kagefusa and Ouka discuss the latters feelings for Muneyuki until they are interrupted by a courier with urgent news. The following day, before the training begins, Chifusas grandmother tells Chifusa the story of how her mother died, revealing that Chifusas mother killed herself so the Manyu wouldnt learn how to use the Breast Flow technique for their corrupt ways. Nonetheless, Chifusa vows to learn the Breast Flow technique in order to undo the Manyus unjust regime.