He needed a wife for his company, she needed money for her family.
"Blaze the last thing I want you to do before I die is marry." Is what Blaze's Grandmother told him. She also told him that he wasn't getting his Father's company without having a girl to spend the rest of his life with, and that's where Sage fits in. Sage was a lower middle class girl, who was helping her mother pay the bills, when she sudden loses her job, she has nowhere to turn to, but I guess that's where Blaze comes in.
I hope that you laugh, are frustrated, and fall in love with them.*Not Edited*