一个大学毕业步入社会的男子，受尽身边人的打击和白眼。在被房东赶出门外的午夜，有了一次神奇的经历，遇到了自称天神的眼镜男，让他变成了他最羨慕的那个有钱人，而身边的人也都发生了角色互换。他开始用转换能力变成他羨慕的人，追寻别人拥有的最珍贵的东西，他寻回内心的置换人生角色之旅正在开始。他一次次用置换人生能力追寻自己的欲望，在追寻过金钱、爱情、亲情等等之后，他幡然醒悟，用最后一次置換机会回到了自己的校园时光，重新找回了单纯、努力、向往明天的自己。
airplanes have replaced cars, numbers have replaced names, pills have replaced food, government-arranged marriages have replaced love, and test tube babies have replaced ... well, you get the idea. Scientists revive a man struck by lightning in 1930; he is rechristened "Single O". He is befriended by J-21, who can't marry the girl of his dreams because he isn't "distinguished" enough -- until he is chosen for a 4-month expedition to Mars by a renegade scientist. The Mars J-21, his friend, and stowaway Single O visit is full of scantily clad women doing Busby Berkeley-style dance numbers and worshiping a fat middle-aged man.
