Nazotoki wa Dinner no ato de is currently my favorite jdrama. An attractive butler (Sakurai Sho), and a spoiled heiress/police officer (Kitagawa Keiko) try to solve mysteries. Kageyama (the butler's name) helps his mistress, Reiko (the heiress) solve the weird cases that she comes across. But he's not so humble that he won't call her an idiot whenever he sees fit.
Sakurai-san is incredibly charming as Kageyama, Kitagawa-san is beautiful as Reiko, and the two of them have excellent chemistry. And yes, I desperately want them to end up together. There's a special coming out in March, which I am ridiculously excited about.