The drama revolves around two police academy students with vastly different identities and four lost youths. Su Ming and Gu Jun are classmates in the police academy. After graduation, the two begin a different path of life and love. However, one day, Su Ming was suddenly terminated from his job and disappeared. Gu Jun initially thought their difference is only due to the disparity in their social class. However, after investigation, Gu Jun discovers Su Ming's secret. (Source: DramaWiki) ~~ Adapted from the novel “Sky Blue” (天蓝蓝).