故事发生在风景如诗如画的贡嘎雪山脚下，阿布（张宥浩 饰）是在磨西小镇长大的小镇青年，经营着一家酒吧，为来当地旅游的游客们提供向导服务。阿布是一个好奇心非常强烈的男孩，喜欢一切他闻所未闻的新鲜事物，某日，阿布邂逅了名为骆瑶（薛昊婧 饰）的女孩。骆瑶是那种非常典型的都市女孩，身上带着明显的只有在大城市生活的人才有的那种疲倦和忧郁的气息，这种气息深深的吸引了阿布，让他忍不住的想要向骆瑶靠近。 骆瑶即将启程回家了，临别之际，阿布向骆瑶许下了诺言，要为她在星空之下建造一座木屋，骆瑶离开后，带着对她的爱意和思念，阿布怂恿了周围的几位好友，开始落实他的计划。

原本家庭幸福的医生林远志（郑嘉颖 饰），因一夜“激情”，陷入出轨的恐慌与焦灼，他试图用谎言来掩盖真相，但“第三者”方瑜（陈静 饰）的步步紧逼和疯狂示爱，则让妻子刘靖（朱晨丽 饰）以及整个家庭陷入各种不可知的致命危险中……

In 1992, a heavy rainstorm caused massive power outage in Hong Kong. At that night, two young astrology enthusiasts, Moon and Sun, met under the starry night by the seaside. When their affection to each other grew, Sun was admitted into a boarding school and would move to another country in a few months under his father's plan. Like the sun and moon, the couple could hardly see each other despite that they were living in the same city, but their love endured amidst the separation and opposition from Moon’s mother. Overcoming the challenges from teachers, friends and family, time has come for Sun to depart…

In 1992, on a small island in Hong Kong, a boy fell for Yan crazily searched for her by dozens of unbelievable means. Although every 'Yan' he met turned out to be someone else, they did bring life-changing influences to each other. 22 years later, when the story is finally unveiled, middle-aged Yan is deeply moved.