At one point in Shogun, Blackthorne and Mariko end up discussing "pillowing", and Blackthorne politely refuses the company of a woman. Innocently, Mariko ends up asking Blackthorne if he wants to "pillow" a boy. Blackthorne is utterly aghast at this, and begins telling Mariko in no uncertain terms that he finds the idea disgusting. Unfortunately, this leads one of the samurai guarding Blackthorne to suggest he might be impotent, and tells Mariko to ask Blackthorne that. The novel does not detail precisely what Blackthorne says, but it evidently involves a lot of swearing. Finally the samurai in the room comes to the brilliant conclusion that because he heard that the "Garlic Eaters" like to "pillow" dogs, that must be what Blackthorne wants to do, before remembering that the rumor includes dogs and ducks. The samurai almost has Mariko suggest that Blackthorne have sex with a duck before finally thinking better of it.