The only japaense words I would unconsciously pick up would be the ones that they say it over and over and over...etc.
That usually sticks on me like glue :)
including
aunt - go-mo
uncle - sam-chun
grandpa - ha-ra-bu-jee
grandma - hal-mu-nee
btw I suck at typing korean in english >_>
(ish the only korean in forums from what I've heard :p)
Anything else? :D