In Japanese, how do you say...?

Question

"You are my best friend and I miss you more than anything. Please come back to me"?

I became really close with the Japanese exchange student but sadly my friend went back to Japan and I would like to say this in Japanese. Any help would be very great^^

Arigatou gozaimasu

Answer 1

Japanese doesn't have a way to express "miss" other than "want to meet."

You are my best friend and I want to meet you [again]. Please return soon.

besutofurendo da, aitai yo. Sugu, kaette kudasai.

ベストフレンドだ、会いたいよ。　すぐ、帰ってください。

You can replace bestofurendo (ベストフレンド) with shinyuu (親友) for the same effect.

Answer 2

あなたが私の親友とあなたがいなくて何よりです。私に戻ってください

That's how you would write it. I don't know how I could tell you how to say it. Just email that to him or something.

Answer 3

You are my best friend and  

あなたは私にとって最高の友であり、

Anata wa watashi ni totte saikou no tomo de ari,

I miss you more than anything.

あなたが何よりも恋しいです。

anata ga nani yorimo koishii desu.

or

あなたを何よりも待ち焦がれています。

anata wo nani yorimo machikogarete imasu.

Please come back to me

私のところに戻ってきて欲しいです。

Watashi no tokoro ni modotte kite hoshii desu.

miss = 恋しい/待ち焦がれる(long for) in Japanese in this context.