Kaede performs the Chichi-togi (Breast Polishing) cleansing on Chifusa's breasts to keep them from sagging after they become increasingly large due to her defeating Manyuu Assassins. However, on this occasion, Kaede tries a new form of Chichi-togi that she thinks will also enlarge her breasts...the boob-on-boob Chichi-togi.

While Chifusa sleeps at an inn, Kaede decides to measure her breasts but gets carried away and begins to play bondage with her sleeping friend. When Chifusa awakens, she finds herself trapped at her breast-crazed friend's mercy, who begins to play wildly with her boobs.

Kaede and Chifusa try different techniques from the Manyuu Secret Scroll to try and enlarge Kaede's breasts. After several failed techniques, Kaede stumbles upon one she likes, which involves sucking milk out of a larger breasted woman's bosom. Chifusa attempts to protect her chest, but eventually gets pinned down by Kaede, who begins to suckle greedily on her chest for the whole afternoon.

After Chifusa's breasts expand too much, Chifusa's clothes stop fitting her and in order to make new ones, Kaede has to make a plaster model of her friend's breasts.

Kagefusa forces Ouka to perform the Chichi-togi on her breasts and recurringly teases her with her bosom. When Kagefusa begins to lactate due to Ouka stimulating her nipples, she tries to spray her milk on Ouka telling her it will enlarge the size of her own chest if she drinks it. However, at this point, it is revealed that the entire sequence was just a nightmare that Ouka had.

Kaede narrates through her journal a whole day of activity during her and Chifusa's travels; which includes descriptions of how they fled from Manyuu Assassins through a forest, by swimming across a lake and finally confronting them and fighting them in a valley at sundown. However, Kaede's descriptions tend to quickly become drabbles about Chifusa's breasts rather than her actions.

After recovering her breasts, Ouka goes to a hot spring to relax and play with her newly found bosom. However, she gets caught by Kagefusa and Kaede, who blackmail her into capturing Chifusa and hold her in place so that Kaede and Kagefusa can suckle on her breasts in an attempt to suckle her milk which, according to the Manyuu Scroll, would enlarge their own breasts.