“Rainbow Eyes” revolves around a serial killer who defies logic, and police scrutiny.
Inspectors Kyung-yoon CHO and Eun-joo PARK have been an inseparable duo ever since their police academy days.
After his girlfriend breaks up with him, Inspector Kyung-yoon Cho throws himself into a murder case that he must solve with his female partner, Eun-joo Park. But figuring out the criminal becomes a harder task than expected. Semen found on the scene indicates mysterious homosexual activity, and the victim’s partners in and around the gym he owns are all playing coy.
The only clue to the case is a piece of body hair with AB blood type found at the scene. The two inspectors identify a swimming instructor as a major suspect to the case, but he later gets brutally murdered in the same way. It is later revealed that the two victims and a third party were once in the same army and committed a disgraceful act together.
The police finally think they narrowed down the murderer, but then the suspect shows up dead himself, in the same vicious manner. Theories and dead-ends pile up, with the killer only being unmasked only at the very end. But to get to him, inspector Kyung-yoon Cho finds that he needs to unmask the real history behind the victims, and himself as well.
The first victim is a sports center manager who seems to have suffered stab wounds. The second victim is a swimming trainer at the sports center, which confuses the police. The second victim’s unexpected death breaks apart the police’s hitherto assumption that the trainer is a key suspect.
Finally, the third murder takes place, sending the police and detective Cho Kyeong-yoon (played by Kang-woo Kim) scrambling for clues. But the serial killer, whose name is Lee Yoon-seo, is nowhere to be found.
As the investigation unfolds, it turns out that all three of the victims belonged to the same barracks when they served in the military. Incidentally or not, 10 years ago, they beat up a soldier, whose name is none other than Lee Yoon-seo, and they were transferred to a different unit due to the incident.
All the signs point to Lee, but he has long disappeared after suffering from some schizophrenic symptoms, obviously initiated by the traumatic beating.
Cast
| Kim Kang-Woo | Gyu-ri Kim | Lee Su-Kyeong | Kim Sung-Ryeong |
| Kyeong-yoon Cho | Eun-ju Park | Su-jin Cha | Hae-suh Lee |
Additional Cast Members:
- Choi Chang-Kyun – Jay Bae
- Oh Ji-Young – Mi-sook Jung (nightclub singer)
- Park Won-Sang
- Jang Won-Yeong – Rapist
- Kim Yu-Jeong
- Choi Deok-Mun


