Is this a loan or an investment?

[Jacob Yates]

I have a private lender or investor, I am not sure what to call him, who has agreed to put 10% down for a 20% ROI paid out in 1yr intervals. I have two questions in regards to this:

1.) What type of lawyer should I get to draw out the contract and what is the estimated cost of hiring the said lawyer (I know it varies just a rough estimate would be nice.)

2.) How should this be classified is it a loan, an investment? Or even a partnership I highly doubt it would qualify as a partnership as all the lender is doing is lending the money. 

My issue with calling it a loan is it isn't calculating out interest, as it is a one time calculated 20% paid back on top of the original invested amount.

Thank you in advance for any input.