Nan-hee finds herself accepting a prize for winning the Spring Literary Contest but it turns out to be a dream as she wakes up from her sleep. In her real life, her mother constantly nags her to quit her job at a publishing company, which doesn’t pay her on time, and urges her to get married. Meanwhile, Nan-hee and Hyung-tae receive an identical text message simultaneously. Nan-hee calls up Hyung-tae after receiving the text message and realizes in mid-conversation that she and Hyung-tae had promised to
spend the last day of their twenties together at Mt. Nam, and scheduled a text message to be sent to themselves a year ago to remind them. She tells Hyung-tae to keep his promise and heads to Mt. Nam. Amid other young couples, Nan-hee tries to get Hyung-tae into a romantic mood but it backfires. No sparks fly between them. And that is how they spend the last day of their twenties.
一直抱作家夢的蘭熙，屢次參加文藝比賽卻都敗北，蘭熙母親對她遲遲不結婚，卻成天空想實在忍無可忍，於是狠下心將蘭熙的作品全都燒毀，好不容易搶救到筆電的蘭熙，與母親大吵一架之後賭氣離開了家。其實蘭熙有一個22歲的大學棒球隊投手男友政洙，但由於年紀的落差，讓蘭熙不敢公開自己的戀情。即將邁入三十歲的蘭熙，對於未來感到相當茫然與恐慌，幸好有青梅竹馬炯泰的陪伴，讓蘭熙不孤單地度過了2005年的最後一天。而炯泰雖然在工作上小有成就，但卻因為忘不了初戀情人星兒而變得玩世不恭。某日蘭熙偶然來到街頭的算命攤，算命師說她與家人相剋，最好快點分家。蘭熙在高中同學的聚會上遇到了初戀情人俊茂，對於一事無成的自己感到有些悲哀，蘭熙與炯泰兩人喝了酒後在路上又唱又跳，蘭熙還在星兒的廣告看板上亂畫一通，卻沒想到就在此時警車來到了兩人面前﹒﹒﹒
