In the early 1940s, the Chinese Expeditionary Force went to Myanmar to fight against China. Jiangnan, a young military doctor, saved Sanglong, a Thai soldier, on the line of fire, and they became friends. Sang Long loves music, and he wrote the song "Misty Rain and Brown Love" to Ni Mei, a favorite bar singer. Jiangnan met Ni Mei through Sanglong's introduction, and they fell in love at first sight. Sanlong learned that Minnie was in love with Jiangnan, and his heart was very painful. Thompson, an American military doctor working in a battlefield hospital, proposed to Minnie, but Minnie's girlfriend forced him to back down with a gun and took it out on Jiangnan and sent him to the front to do battlefield rescue.

Jiangnan bid farewell to Minnie, and Minnie gave her mother's gold necklace to Jiangnan as a token of love. The two vowed that the honest and kind three dragons could only swallow the bitter fruit of love and bless their friends. Jiangnan stole Thomson's car to save Lin Yuru's life, and was shot. Thomson saved him himself. Jiangnan returned from the front and reunited with Minnie. The fire of feelings could not be controlled, and the two stole the forbidden fruit.

Minnie was very sad that Jiangnan was disciplined. She resolutely left the bar, joined the expeditionary force and became a nurse in a field hospital. Her outstanding performance in the field hospital won the unanimous love of the wounded, and "Misty Rain and Brown's Love" has also become a song widely sung in the field hospital. Cheng Yiren, president of the battlefield hospital, sent Minnie to work with Thomson in order to please him, and sent Jiangnan to the front again. Cheng Yiren was reprimanded by Thomson. Lin Yuru, a female soldier who returned from injury, fell in love with Sanglong, who donated blood for her healing, and met again after the war.