In Japanese, a "stomach bug" isn't a sickness, but rather "a bug that stirs up one's feelings."
I'm sure you know 虫 means "bug" or "insect," but idiomatically, it also can represent that something inside us that stirs feelings up. Think of it as a "non-bug bug in one's gut" that stirs up emotions.
Today, we'll look at a few idiomatic expressions involving 虫 (the non-bug bug in one's gut)
Before we do, did you know, in addition to the Names course, we also have a Makoto+ Japanese Idioms course. If you want to improve your Japanese idiom knowledge, give it a try. Free for Makoto+ Shogun and Lifetime members, $10 for Samurai members, and $29 for the non-member price. Click here to learn more about Makoto+
The 虫 bug here refers to the Taoist belief that three worms lived inside the human body. The worms keep record of their host's misdeeds and report the transgressions to heaven. You can learn more about it here: https://en.wikipedia.org/wiki/Three_Corpses
Knowing this, you can see why most of the idioms using 虫 are negative.
Let's hit on a few useful "non-bug bug" idioms.
selfish; asking too much; take too much for granted
He is always asking for too much.
- 彼は as for him, he…
- いつも always
- 虫がいい take too much for granted
- こと matter [creates a noun phrase]
- 言っている saying
And here is the same form but いい is conjugated with すぎる to mean “too good”:
asking too much; very selfish
Don’t you think that’s a little selfish?
- それは as for that
- 虫が良すぎるん too selfish [The ん is used to both soften the criticism and ask for agreement]
- じゃないか isn’t it?
staying angry; cannot contain one's anger; can't contain myself
Even though his friend apologized profusely, he was still angry.
feeling in one's bones; foreboding; premonition
I had a feeling this might happen.
- 虫の知らせ feeling in one’s bones
- があった there was
to be disgusted; to be repulsed; to get the creeps
Just thinking of that pervert’s face gives me the creeps.
Mom was irritated so dad quietly snuck out for a walk.
disliking; having an antipathy to
No matter how hard I try, I just don't like Tanaka.