[Essay] Not Even a Shell Left Behind
"Monuke no kara" (empty shell) is an idiom used to describe something that is completely empty. It is often used by detectives who step into a house after a criminal has fled. (Example: "They got away! The house is an empty shell!")
By the way, what is a "mo"?
"Monuke no kara" must mean a "shell" from which a "mo" has "escaped" (nuketa). I suspect that there was an animal called a "mo," and that the "mo" had a habit of slipping out of its "shell." The ancient people who saw the "shell" left behind by the "mo" must have been frustrated and said, "Darn, it's an empty shell," which must be the origin of this idiom. The fact that they were frustrated suggests that the "mo" must be quite delicious. It must definitely be a high-end ingredient.
Since it has a "shell," could it be a crustacean? Perhaps it carries a shell like a hermit crab and moves to a different shell when its body grows... Wait, isn't that just a hermit crab? Was "mo" actually a hermit crab?
Or perhaps it refers to a reptile that molts. Snake skin or lizard skin, when dried out and crispy, could arguably be interpreted as a "shell." They say that in rural villages, people open up snakes and eat them like eels, so it wouldn't be strange if there were a delicacy snake called a "mo." A snake, huh? I might actually want to try eating that.
Thinking about things like this, I searched for "monuke no kara origin" on a search engine.
"Monuke" refers to the molting of cicadas or snakes, or the shed skin itself; the latter is synonymous with "monuke no kara."
It wasn't a "shell" of a "mo" that "escaped," but a "shell" after something had "molted" (monuketa)...! I never imagined that "monuke" was a single verb. According to the Etymology Dictionary, the origin of "monuke" is likely "mi-nuke" (body escape) or "koromo-nuke" (garment escape), so the true identity of "mo" is either "body" or "garment." I see, no wonder I couldn't find an animal name.
Mystery solved. Now I can use the phrase "monuke no kara" without worrying about the identity of the "mo." But I am just a little sad that the phantom delicacy "mo" that leaves a shell behind has disappeared.