Necessary
Shaving the hair off a geoduck before you try to eat it is absolutely necessary. If you don't, the hair will get caught in your throat and you'll choke. It is necessary that you remove the hair.
す, しゅ
すべから, すべし, ひげ, まつ, もち, もと
None
It is also necessary that you wear a suit (す) when eating shaved geoduck. It's a super fancy meal so a suit is necessary for you to enjoy it correctly.