『夫妻成長(chang)日記4』介紹:在(zai)金(jin)槍大賽(sai)上(shang)榮獲冠軍的尹名揚(yang)(呂頌(song)(song)賢(xian)(xian)飾(shi)(shi))與同(tong)窗好(hao)友(you)方正(zheng)(zheng)(zheng)(zheng)一同(tong)追查炳(bing)爺等(deng)人(ren)的犯(fan)罪證據,結果遭遇身手(shou)敏捷(jie)的女殺手(shou),阿(a)(a)正(zheng)(zheng)(zheng)(zheng)右手(shou)中搶傷殘,阿(a)(a)揚(yang)則被蒙面人(ren)槍殺身亡。在(zai)此之(zhi)后,阿(a)(a)揚(yang)的弟(di)弟(di)尹平安(呂頌(song)(song)賢(xian)(xian)飾(shi)(shi))受(shou)調(diao)歸國,進入兄長(chang)生前所(suo)在(zai)的部門。在(zai)一次執行任務時,他遇到(dao)女殺手(shou)陳小(xiao)(xiao)明(萬綺雯飾(shi)(shi)),她正(zheng)(zheng)(zheng)(zheng)是(shi)打傷阿(a)(a)正(zheng)(zheng)(zheng)(zheng)的兇手(shou)。與阿(a)(a)揚(yang)相(xiang)貌(mao)相(xiang)似的阿(a)(a)安令小(xiao)(xiao)明心有(you)所(suo)動,而阿(a)(a)安也(ye)為(wei)眼前的女孩(hai)所(suo)傾(qing)倒(dao)。不(bu)(bu)久,重(zhong)振(zhen)信(xin)心的阿(a)(a)正(zheng)(zheng)(zheng)(zheng)返回警局,和槍房的楊近東(dong)(秦沛(pei)飾(shi)(shi))一同(tong)訓練(lian)阿(a)(a)安,加上(shang)接連不(bu)(bu)斷的突發(fa)事件(jian),阿(a)(a)安的槍技突飛猛進。隨(sui)著時間的推(tui)移(yi),阿(a)(a)安和小(xiao)(xiao)明這對警匪的愛情也(ye)在(zai)周(zhou)折中發(fa)展。與此同(tong)時,槍殺阿(a)(a)揚(yang)的蒙面人(ren)也(ye)漸漸浮出水(shui)面,一場(chang)恩(en)怨終有(you)了斷……