Hey Joe!
I met you on May 2nd at Big Joy Family Bakery & Cafe for the first time. It has been almost 8 months since we know each other. Actually, you're the first friend in the U.S. I must say, I learned a lot of things in English from you. Thank you for as always being such a good friend. I will never forget you've done to me. I owe you. I have a duty to learn English even I'm back to Japan because I don't want you to be disappointed. In the future, I'm looking forward to grading a beer with you in Japan. I wait for you. See you soon, Joe! soa natural?

I can understand it fine but let me correct a few things.

"...almost 8 months since *we've *known each other."

"Actually, you're *my first friend in the U.S. *and I must say, I learned a lot of things *about English from you."

"Thank you, as always, for being such a good friend."

"I will never forget *what you've done for me."

"I have a duty to learn English even *when I'm back *in Japan because I don't want you to be disappointed."

"I'm looking forward to *having a beer with you in Japan *in the future."

"I will be waiting for you." sounds better than "I will wait for you."


You did a great job though! I hope you enjoyed your time in the USA :).