I've taught English in Japan for almost 9 years. I know a lot about the difficulties of learning English and what techniques are helpful for people who's native language is Japanese. I can speak Japanese but I will only use it if absolutely necessary. I think it is important to keep an all-English atmosphere during the lessons.
I can help improve your English conversation skill, pronunciation, reading, writing, etc.
I also offer lessons to learn to sing your favorite English songs. This would be held either on Skype, in your home, or at a Karaoke place.