阿东（张智霖 饰）、阿郎（葛民辉 饰）和布拉德（许志安 饰）是同居一室的室友兼好友。阿东和女友（汤宝如 饰）相恋多年，彼此之间感情十分稳定。然而，这段波澜不惊的感情却令阿东感到乏味和疲惫。
某日，阿东偶然之中遇见了久别的漂亮表妹，热情活泼的表妹很快就吸引了阿东的注意，在表妹身上，阿东寻得了久违的激情和重获青春的感情。然而，女友对自己的依恋让阿东无法和她说出实情，夹在两个女人之间，阿东苦苦无法做出选择。布拉德向来喜欢流连于莺莺燕燕之中，风流快活，哪知道一位神秘女子的出现，竟然让一向洒脱的布拉德陷入了苦恋之中。

The "Hu-Du-Men" (loosely translated as "stage door") is an imaginary line separating the stage from reality, and a line that must be crossed each and every night by Sum (Josephine Siao), the aging star of a Cantonese Opera troupe. Nearing the twilight of a storied career, Sum must face a variety of challenging new obstacles, including the possible emigration of her family come 1997, the appearance of a promising young actress (Anita Yuen), the hiring of a Western-schooled stage director (David Wu), the surprising revelation of her daughter's sexuality, and finally the reappearance of a shocking secret from her past. Through it all, Sum must retain her professionalism and dignity, as the "Hu-Du-Men" between the stage and her life begins to blur. Emotional, intimate direction and Raymond To's intelligent, relevant screenplay make Hu-Du-Men worthwhile cinema, but it's Josephine Siao's brilliant, emotionally dynamic performance that sets this film above the rest.

家声（林子祥 饰）已经四十六岁了，至今仍未成家。他青梅竹马女友丽泉（伍咏薇 饰），要求与他之间做个了断。两人多年来没有结果是因为家声是一名同性恋者。而家声是有一名男朋友Sonny（陈小春 饰）的，但Sonny十分享受花花世界给他带来的虚荣，这样便使得家声觉得十分没有安全感，却又对Sonny的感情越来越深。
家声一名同性恋好友永烈因艾滋病死去了，家声劝止永烈的男友（吴镇宇 饰）不要出现在丧礼上，却被Sonny从中捣乱，家声也因此与Sonny分手了。
但家声复杂的感情世界并没有因为这样得到解决……