"Yukkuri" alone may mean "easy/in a relaxed manner" "slowly" "a Yukkuri(creature)" "verb of not precisely defined meaning, roughly meaning 'behaving in a way appropriate for a Yukkuri'" "adjective denoting the object has Yukkuri qualities"(circular definition FTW!)
It may also mean the same thing as "smurf".
It's heavily context based. And some translators leave it as it is because they are not native speakers in English, or don't trust their own literary talents as much as they trust the anonymous to finish the job.
Actually, non-native speakers have an advantage when it comes to yukkuris, since they have no qualms about utterly butchering English grammar and spelling to match the yukkuri slurring standards.
Redo this with people, and it's still a possible scenario. Man walks into house where the father isn't home, eats food, hangs out, rapes daughter, etc. Bastards are getting more human. Also: KILL THE MARISA! KILL! KILL! KILL!