Rainbow Eyes () is a 2007 South Korean crime thriller film directed by Yang Yun-ho. The story follows a police inspector who discovers that his friend is now a serial killer. The movie was remade into a Thailand thriller named 'Cheun'. Plot Kyung-Yoon (Kim Kang-woo) and Eun-Ju (Kim Min-sun) investigate a grisly murder of an affluent entrepreneur. The victim was slashed over 20 times, and there was blood everywhere in his apartment. The killer was careful not to leave behind incriminating evidence, but a strand of the killer's hair was found. The police are then able to determine that the killer is male and has an AB blood type. Kyung-Yoon's personal life is also given priority, with his girlfriend asking to break up with him, saying that he loves someone else and called their name when drunk. Shortly after the first grisly murder, a second murder occurs. The victims seem to be unrelated, but the modus operandi seems the same. When the police delve deeper into the victims' background, they discover that the two victims were stationed at the same military base many years ago. A month prior to their discharge, they were transferred to another base along with a third man named Jong Ha. The police now believe Jong Ha could be the next victim or the killer. However, their investigation has only led them to Kyung-Yoon's old friend, Yoon-Suh, who was in the same military base and shot himself. The transfer of the trio happened after. It is revealed through a series of flashbacks that Yoon-Suh was gentle and effeminate. Kyung-Yoon protected Yoon-Suh from bullies but eventually stopped when he got into a fight and got beaten up. He tells Yoon-Suh to man up. Kyung-Yoon independently tracks Yoon-Suh. He contacts Yoon-Suh's old military acquaintance, who reveals that Yoon-Suh joined the military only because someone told him to man up. From there, he was abused and raped by the trio. Kyung-Yoon goes to Jong Ha, who angers him, saying that Yoon-Suh was passed around from bed to bed and everyone had him. He does not apologize and instead makes light of it and laughs, which drives Kyung-Yoon mad, and he gets into a scuffle with them. Later, Kyung-Yoon is seen bruised, and Eun-Ju calls him, saying Jung Ho was found dead. Kyung Yoon is convinced that Yoon-Suh got a sex change and murdered them. Kyung-Yoon talks with Yoon-Suh's sister,