dugeun dugeun daejakjeonDugeundugeun Daejakjeon; The Heart-Pounding Operation; 두근두근 대작전; Operation: Heart-Beat; Chiến Dịch Rung Động Trái Tim; Operação: Coração Acelerado

"Don't you think we're missing that heart-fluttering feeling?" From elementary school all the way to high school, Nam Do-yeon and Jeong A-rin have gone from childhood friends to lovers. For a couple who strives for a perfectly rational relationship, a plan to reclaim that one missing piece of excitement Operation: Heartbeat begins!