Changing student visa for unpaid internship

Greetings,

Currently, I am studying at a language school till the end of December, the company I have been doing part-time internship has offered me to change the contract into full-time unpaid internship from January till November as my current student visa expires on 2019 November.

Did research for the different type of Visas to switch for the internship but the problem is that I do not have a bachelors degree and could not figure out for which to apply for. would cultural visa or another type of Visa can be appropriate for this situation?
My mentor is going to make a call next week to the immigration office but beforehand, I would appreciate if you could give me some recommendations so we could prepare better for the call with more facts.

Thank you in advance.

"the contract into full-time unpaid internship from January till November�h
9 months are so long as unpaid internship. since you also say full-time, it seems to be illegal to labor law.
your student status is valid only when you attend the school. if you quit the school (you get a full-time internship), you have to find a new school within 3 months. even if your Zairyu card says your student status is valid until November, 2019, your stay in Japan becomes illegal.

Internship can be training but should be paid. If unpaid that sounds strange for that time period without school.