There are many, many types of visa. Do you mean a Dependant Visa? If so then it must be a relative. Exactly which relatives depends on whether the sponsor is a Permanent Resident or not.
HK non-permanent residents can sponsor Dependants who are their legal spouse and dependant children.
HK Permanent Residents can, in addition, sponsor their parents if they are over the age of 60.
I am trying to apply for investment. But since my company is so far one-person company (me) - which means I can't have "in-company-employee sponsor", I am just making sure what options are no-no not to waste time on them. And I currently cannot hire anyone local, as I am not allowed to do business in HK (my current visa status doesn't allow it).
If you don't have a registered business then you can't get an Investment Visa. Sole proprietorships don't count for Investment Visas. If you have a registered company then you must have at least one other person involved (one director and one company secretary is the minimum) so assuming you are the director then your company secretary can be the sponsor.
Q15 in the guidance notes lists the documents you need to provide with your application.
