Palm
If you want to cover a Viking's mouth with your hand, you have to use your palm. Why the palm? Well, if you do it knuckles-to-mouth, you're sort of just punching the Viking… and you don't want a punch a Viking. That's why you use the palm.
しょう
てのひら
None
This Viking-touching technique of using the palm was developed by the Shougun (しょう). The Shogun has to deal with a lot of loudmouthed Vikings, so he's learned to use his palm to cover their mouths.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.