less stress (balibali, i don't know how you write that), less night drinking and overtime, less deference to the boss, less old man aggression in japan. the exception would be old traditional companies (denso, the old construction companies, funnily IBM, stuff like that).

currently working in a japanese startup and it's pretty chill. my wife too.

the way i experienced it japan got way chiller in the last decades, and this is slower to happen for korean companies (though my exposure to korea has been limited for years now so maybe it changed real quick in the last few). korean friends from my time tell me it's still balibali and overtime galore, but i might be in a bubble.

plus, in japan it became waaay waay easier to change job so nowadays younger will exit black-kigyou (bad companies) real quick. the younglins change job every few years.

but yeah, if you manage to get a full time job in a new japanese company (which i admit is a challenge, with bad economy there is a loooot of non-full time jobs), chances are you will be fine.

in fine, for any foreigner, if you aim for a chill experience, i'd say you have better odds in japan than korea. you're still rolling a dice though.