父親在捷運局工作的小倢(紀培慧)，人生各個階段，似乎和捷運的發展有著密不可分的關係。然而，與捷運的快速世界不同的是，小倢的世界是慢的，心也是慢的，情感、反應和動作也常被嘲笑慢了世界一秒鐘。
小倢有兩個夢想，一個是將自己的畫作出版，一個就是能和那個她經常在捷運站相遇的男孩說上話。直到那一天，她在北投車站，上了一台「限時專送」的摩托車，認識了這個堅信世界應該要有「平行時空」的男孩，她的夢想，終於有了實現的機會。
然而，每一個捷運的轉乘分岔點，都有如小倢人生選擇的轉捩點。這些轉捩點會帶著小倢走向愛情，或走向人生不可預期的改變？如果，這個世界，有平行時空的話，那麼，在這個個性溫吞內向的小倢的世界對面，會不會有另一個小倢、小傑或小潔，也過著一樣的日子，一樣的心情，那麼他，面對人生的改變，會有什麼不一樣的決定嗎？
這是一個孤單的城市，每個人孤單的理由都不一樣，面對孤單的方法，也每個人各有不同。小倢和爸爸相信，人生，就是一段在「你好」和「再見」之間的故事。有的人短暫同行，有的人相伴扶持…但無論如何，在這趟旅程當中，我們幾乎永遠都是孤單獨立的。而這城市的孩子，小倢、小剛，他們…正在尋找面對寂寞的方式。

The drama is adapted from the same-titled youth and passionate sports competition novel by author Chang E from Jinjiang Literature City. Doctoral student Lin Wansheng suddenly returns to his hometown and takes up a job as a sports equipment keeper at Hongjing No. 8 Middle School. Wang Fa gives up his job as a coach at a British football club and returns to Hongjing, becoming Lin Wansheng's mysterious tenant. Lin Wansheng is asked to lead the disbanded football team to participate in the league. As expected, they are beaten to a pulp. Thanks to Wang Fa's guidance, they manage to win the game with great difficulty. After that, Lin Wansheng persuades Wang Fa to become the coach, gathers the team members and resolves the internal conflicts. When everything seems to be on the right track, the old wounds of Wang Fa and Lin Wansheng are successively exposed. Both of them choose to escape, but eventually they understand each other. The final of the children's football match and the college entrance examination are approaching. The two join hands to help the children regain their love for football, strive for the college entrance examination and embark on the road to pursue their dreams.

漫画家卫枝意外卷入丑闻，被公司没收了笔名和作品版权。消沉的她偶然看到一段单板滑雪视频，被滑雪选手无畏的精神打动，决定以滑雪为题重新开始创作。她前往北山雪场采风，邂逅了教练单崇。在跌跌撞撞的滑雪练习中，卫枝磨炼出了不服输的意志，也喜欢上了教练单崇。单崇曾是职业单板选手，却因妹妹残疾、自己受伤，在父母强烈要求下忍痛退役，心中却始终藏着对单板滑雪的热爱。目睹卫枝面对热爱的事业不服输的倔强与冲劲，单崇决定重回训练场，为心中的热爱与荣誉而战。最终，卫枝赢回了名誉与作品版权，单崇以金牌回报了所有的汗水与期待，两个年轻人也走到了一起。