You'll miss me, won't you? lol
I feel sad, too. I've been around for three months but only these days have we been good friends. I'm very shy but because you talk to me a lot, I am really glad. I really enjoy talking with you. I even could tell you my secret and I truly trust you. Because of cultural differences, I do not think I should trust people in other culture, but among those people, you are the one I can trust most. After I go back, please take care of Miki. She is my important friend, so if something should happen, please help protect her.
I do know that you take care of people. You are kind to others. Even if someone talks against you, I know you are the best person in me. I will never forget you even after I die. Meeting you was the best thing in my life. Thank you. See you somewhere someday.
以上でいかがでしょうか?
補足
いつもありがとうございます!至急もうひとつ英訳してほしいものがあるので同じ質問名で検索して回答して頂けたら助かります。もちろんそちらもベストアンサーにします。