Dear Sir or Madam,

My name is Shin from Japan.
I am planning to go to Spain to do an internship at Spanish design firm in Madrid.
The internship is unpaid and will last at least 6 months.
I have already got an offer for the internship from that design firm.
I am Japanese and I understand I need to obtain a visa for staying in Spain more than 90 days.
I asked Spanish consul in Japan, and they replied me that it is not able to obtain a visa for an internship.
One of the possible way is to obtain a student visa by studying at Spanish language school,
but it costs about 9,000€ for 6 months and is too expensive just for getting a permit to stay in Spain.

I found a Japanese person who was doing an internship last year in Spain for one year.
He told me that he obtained a student visa (tarjeta de estudiante) as an intern at a company.
For obtaining a student visa as an intern, the company submitted a document which they would employ him as an intern.

1. Is it possible to obtain a student visa as an intern at a company in my case?
2. If it is possible to obtain a student visa as an intern at company, what I should do to get it?
3. Is it possible to obtain a working visa in my case?
4. If it is possible to obtain a working visa, what I should do to get it?

I would appreciate any suggestion.

Kind regards,
Shin Sawada