Tang Wan-tung, the son of a Southeast Asian Sultan is a student in Hong Kong. Only Uncle Mui, his guardian, knows his identity. Tang is known as "student prince". He organises an embassy variety show. Tang invites Lai Tsi-king, who has a lovely voice, to perform in it, but it ruins her chance to study music abroad. Lai’s parents want her to marry Tung Fook-si, the son of a merchant. Lai asks Tang to act for her parents, like a prince courting her. Her parents are convinced, but Tung is not fooled. Tang smuggles Lai out to perform in the embassy. Lai's performance earns her a chance to study overseas, but her parents will not support her. Tang borrows money from his father, but is refused. He pawns his father’s ring to help Lai pay the tuition. Tung takes his father's ring and sells it. Tung's father alerts the police. The rings turn out to be a pair. The police think Tang stole the diamond ring, but Mui tells the truth. Tung is arrested and Tang and Lai have a happy ending.