"One and a Half Summer" tells the story of a young man named Zhang Hao (Nichkhun) searching for the love of his life that he met in Santorini during a vacation to Greece. Believing that he was destined to be with this mysterious woman, he went all the way to China from New York just to find this mystery girl leaving her college handbook by the name "Luo Man" whom Zhang Hao went looking for at Nanyang University. Zhang Hao immediately found out, however, that "Luo Man" was perhaps another woman whom he never knew before. At this junction, Zhang Hao decides not to give up searching for this peculiar woman.  During the quest, a band consisted of Zhang Hao, Li Xiuqi (Jiang Jinfu), Ma Juncai, Wen Tingting, and Wang Minqiang was founded by Luo Man. During this time, many love couples were also formed including that of Ma Juncai (Weida Xun). Conjointly, Luo Man secretly fell in love with Zhang Hao despite being always mad at him. After a series of fortunate and unfortunate events, Zhang Hao eventually found the mystery woman under the name of Shu Qing (Yu Wenwen) who was already engaged at the time. Zhang Hao was put into a deep crisis after being denied and rejected by Shu Qing, but nevertheless learned to move on as time passed by.  After Zhang Hao finally came forward, Luo Man incidentally revealed her feelings towards Zhang Hao. Due to this, a tension between Li Xiuqi and Zhang Hao came into picture because the feelings of Li Xiuqi for Luo Man was revealed later on. Zhang Hao decided to give way for Luo Man's childhood friend Li Xiuqi, but at a later time realized that he cannot bear hiding his feelings for Luo Man as well. As Zhang Hao was about to confess his love for Luo Man, his mom called him to go back to New York, otherwise he will not be able to graduate and thus averting him to blurt out his feelings.  After their final band performance, Zhang Hao bid his goodbye with his friends which totally shocked everyone. Luo Man was especially hurt knowing that their romantic relationship, although haven't even started, had already ended. One year later, a gathering was held at Santorini where they all had a reception except Luo Man. It was told that Luo Man traveled across various countries, leaving his school friends behind. In the end, while Zhang Hao was talking to Li Xiuqi, he coincidentally sees Luo Man walking at the beach front.