"My Dear Enemy" is an exercise in subtle comedy, anchored by the delightful chemistry of the pitch-perfect lead performers. Jeon Do-yeon, as the sensible, even-tempered Hee-soo counterbalances the hysterical mother of a murdered child she played in "Secret Sunshine", for which she was named best actress at Cannes in 2007. Ha Jung-woo, too, is winning as the compulsively charming, if unfailingly inept Byung-woon (a role also in stark opposition to his previous outing as the serial killer antagonist in Na Hong-jin's "The Chaser").