Working visa as a Hostel Helper for Filipinos

Hello everyone! Hope you're doing fine.

I received an email from an owner of a Japanese Hostel in Japan telling me that they would like to accept my application as a hostel helper. However, when I asked if they can sponsor my working visa, they told me that they do not sponsor any working visa. They told me that the only possible way that they can help is to sponsor a change from a working holiday visa to a working visa. Unfortunately, obtaining a WHV is not yet possible for us Filipinos. Hence, this question as to the requirements for a working visa as a hostel helper. I am thinking that if the requirements and steps for getting a working visa is almost similar to changing a WHV to a working visa then, they may still probably agree to sponsor my application. Do you also think so?

I am really hoping for your reply. Thank you very much in advance!

There is work visa category for such job because it is an unskilled labor job. I can hardly imagine the immigration giving a work visa even if you started with a working holiday visa.

If you work for an English speaking receptionist, you apply a "Engineer/Specialist in humanities/International services Visa".
If you work for a cleaning staff, unfortunately, there is no visa for that job (even WH visa holders cannot apply or change visa, only way is marrying Japanese and get a spous visa).
http://www.mofa.go.jp/j_info/visit/visa/long/visa1.html
http://ishijls.webnode.jp/english/syukastu/

Excuse me, I correct my answer above.
I missed "Helper" you mentioned, do you mean you got a part time job offer?
If so, I do't think you are eligible to apply any work visa.
If you hold a student visa and work parmit but you want to apply a work visa because you got a full time position, I am sorry, it is impossible also.