Young Ji was just being a nice girl with a kind heart, trying to help one of her friend's old friend out of the rut he was in. Jackson is the same aged guy who had gambled with his life and needed this one chance to work himself out of it. 

They seal the deal, on the very first day they met, in a coffee shop where their mutual friend stands witness. 

They didn't think it would lead them down so many slips and turns with no end- nor beginning- in sight.