source- https://www.dlsite.com/maniax/circle/profile/=/maker_id/RG14831.html
Artist- https://www.pixiv.net/en/users/29088547/artworks

premise- On a beach at night, an ama (female diver) unfortunately encounters a kappa.
The ama manages to win the one-on-one battle, but in doing so, she cuts off the kappa's arm, which is still clutching its shirikodama (a mythical organ believed to be
located in the anus). She tries to pull the kappa's arm out of her anus, but... This story has no direct connection to the
nighttime beach fantasy battle "Kappa VS Ama." While there is a depiction of pulling an arm out of the anus, there is no gore or scatological content. 18 pages. Includes textless version .