[Note to Japanese speakers in the forum:]
I'm curious about this, too, although I suspect it will be hard to find something which has the same feeling as the English.
Although "gee" and "jeez" both derive originally from "Jesus," and once had the meaning of considerable surprise (あっ or あら, perhaps?), it is now more commonly used to express mild surprise, sometimes with a tone of sheepishness or self-deprecation.
gaaragaara,
Maybe it would help to give an example or two of situations in which you say this? It's not your standard greeting, is it?
