喉元事案
nodo.moto.ji.an
Literally: throat – origin – think – plan
Alternately: Superficial thinking. Rash and hasty ideas.
Notes: Derived from the belief that one’s deepest thinking was done in the chest. The throat is more “shallow” than the chest, so it stands to reason that it would be the origin of more rushed and shallow ideas.

I dunno; kappa need water, so this doesn’t seem like a bad idea. Image from a Vietnamese site translating yojijukugo.