Improve!

Q: Can I improve my English in 3 weeks?

A: Yes you can, and here's why--

You already know a lot of English. You have studied it for years, but living in Japan, you don't have a chance to practice everyday.

Everyday when you do a homestay, you will use the English that's already in your head. You will speak to your host family. You will speak to your host family's children. You will have 5 hours of English classes each day where you will use your English.

You will ACTIVATE the English you already know by using it extensively. When you return to Japan, you will be a better user of English. You will understand more in your English classes, and you will understand your English homework better. This will make your motivation for English greater.

What you need are chances to speak English in meaningful situations. Study abroad and homestays give you these chances.