Lee Hwi-hyang

When Jung-ha loses her husband in an accident, Naru, her husband's secret lover, comes to her. Naru begs Jung-ha that she will do anything if only she will let her stay at her house. Jung-ha denies her at first, but eventually their strange arrangement of living together begins. (imdb)

After being diagnosed with a possibly terminal brain tumor, Kang Hye Soo, a desperate single mother, agrees to be a liver donor for her new boss’ mother. In exchange, she will receive a significant sum of money that she hopes to leave to her daughter. In order to pass the screening process, they must legally wed and convince the hospital that they’ve been in a long-term relationship (mydramalist.com)