Eun Sun-Woo (Jung Il-Woo) is extremely smart and surprisingly athletic. He owns and runs Eungang Group, which is the biggest company in Korea. He also secretly runs a private detective office as a private detective. He is gentle, but sometimes arrogant. Don-Se-Ra (Kwon Yuri) was born with hyperacuity. To hide her condition, she always wears glasses.She uses her ability to secretly help people. Even though she is poor, she is bright and doesn't hesitate to help others. Eun Sun-Woo and Don-Se-Ra get involved with each other. While they investigate cases together, their relationship develops romantically.