Studying might be difficult. All of the above. Studying abroad might be more expensive than studying in Japan particularly if you are living with your parents. Studying abroad today is relatively cheaper now than long time ago. Studying abroad in developing countries is more expensive than studying in advanced countries.
Many universities have exchange student programs.
Students with different levels of proficiency are in the same language classes. Classes are taught in the language of the country you are in. You will learn listening, speaking, reading, and writing intensively. You will spend 20-30 hours in class. You will have activities in only classes.