Beautiful, workaholic Bo-hee is a successful marketing executive at the number one toy company in Korea. Respected by her colleagues and in line for a promotion, she makes an irrevocable mistake that gets her fired from her job. Bo-hee's life further spins out of control when her husband Gang-sung leaves her soon after. Bo-hee is befriended by her neighbor Nan-hee, an amateur sex expert who runs a sex shop on the brink of bankruptcy called "Casa Amor." Nan-hee's predicament inspires Bo-hee's creativity, and using her background in children's toys, she is determined to save the shop by making its ambiance more refined and by promoting better sex toys.

The story takes place in Seoul, 2011. Lee Yoon-sung is a talented MIT-graduate who's working on the international communications team at the Blue House. He encounters dangerous situations while solving a variety of cases, both big and small, for people who need his help, and eventually becomes a "city hunter."