Yuri,

Thank you vey much for your help! Can you please help me with one more short phrase - "Come back soon", I know it sounds like "Itte irashai", but I need it in Japanese.
Thanks!

I need to know the situation and the speaker’s gender.

If a wife says to her husband when he leaves home to work, come back soon is;
「早く帰ってきてね」

But it is a female’s way.
If you are a man and say things like that, you sound like a gender identity disorder.

A man would say to his friend who is going abroad;
「早く帰って来いよ」
But this sentence sounds like that you think your friend’s dream is not very important.
If I were a man, I would say: 「頑張ってこいよ!」 or 「頑張れ!」These sentences sounds that you think your friend’s dream is great.

「行ってらっしゃい」is also good, but it sounds a woman’s saying when your friend is leaving your country. A man don’t say 「行ってらっしゃい」to his friend.

Tell me your gender.

Yuri,

I am a male, and my friend going to Japan is a girl. By saying "Come back soon" I want her to know that I am waiting for her (but this sence should be hidden). So it is more like "Good Luck & come back soon!"

Thanx!
Asias

If you are relatively delicate, 「頑張って来いよ！」will be good.
If you are relatively generous,「頑張って来い!」will be fit.
頑張って　is usually translated as “Good luck” or “Give it your all”.
来いよ/来い in these sentences implies the listener will come back.

If you prefer to be polite and formal, 「頑張って来てください」.

It’s your choice!

Thank you very much Yuri! Your help is of real value for me! :) (F)

*makes teasing whipping noise* ;)

(I lived abroad from my girlfriend—now wife—for a year, so I'm just kidding with you.)