Dear XX：
I miss you so much when I'm writing this letter.
We had a good time in your hometown.You took me to a music concert.What's more,this is one of my favourite bands.And they provided such a fantastic entertainment.That's cool!
I really appreciate what you do.
And now,I can't wait ,you know,to invite you to my home to spend a nice day with me.I will give you a surprise.
Yours