Reposting translation.
*still gets excited listening*

Dokimiki Night
Summary
My letter:
To Mikitty,
Good evening. I'm an American who is teaching English in Japan. The other day I saw last year's Morning Musume Dokyu. I'm very impressed by your “Amazing Grace.” I think it's amazing that you were able to remember an English song in one week. Also, I think your pronunciation was perfect. Do you want to challenge singing an English song again? I want to get better in Japanese. Let's do our best!
Reply: It's about Musume Dokyu, but I learned Amazing Grace in a week. The teacher who taught me the how to pronounce was only for two days one hour each day and remembering the lyrics took everything. Well, well, well, isn't it great that an American thinks my pronunciation was perfect?! I don't think it was perfect... I think this teacher is a really, really kind person. I think it will be fastest if this teacher teaches me English and I teach [her] Japanese. Recently, I'm taking a break, but I have thought of wanting to do my best again. Thought.