...and this is how you pull off an expressionless tantrum.

That tantrum is adorable.

This is the best tantrum I've seen.

That 3rd panel isn't expressionless.
Not that I mind though.

What about a "Kokoro is not so expressionless" pool?

[KN] said:

What about a "Kokoro is not so expressionless" pool?

No, we already have an expressionless tag, and you can search for -expressionless as well.

S1eth said:

No, we already have an expressionless tag, and you can search for -expressionless as well.

This very picture shows how this idea can't catch all the instances where Kokoro shows some emotion.

You can't have everything. There will always be exceptions.
That still doesn't make it a good idea.

Showing expressions is assumed to be the default and being expressionless is more rare. That's why expressionless is useful. A pool for a singl character being not epressionless is not useful. And there are many other characters who usually don't show expressions that did not need a pool either.

[KN] said:

What about a "Kokoro is not so expressionless" pool?

Got

[KN] said:

What about a "Kokoro is not so expressionless" pool?

you covered bro!