The passionate old lady Luo Yufen (played by Luo Wenji) has a straightforward personality and loves to fight for justice. For many years, she has focused on reporting illegal acts in the community and is called "Ghost Grandma" by people around her. Her "opponent" is Park Min-jae (played by Lee Je-hoon), a new grassroots civil servant in the Petition Office. The two quarreled and did not decide the winner. One day, Grandma Luo suddenly "shamelessly" asked Park Min-jae to be her English teacher. Because she has a younger brother who grew up in the United States and does not understand a word of Korean, Grandma Luo can only communicate with him after learning English. During the learning process, Park Min-jae and Grandma Luo's relationship became more and more harmonious. However, Min-jae learned that Grandma Luo's brother actually did not want to talk to her at all. In a conflict, he accidentally told the truth to his grandmother. However, at this time, Grandma Luo had a more urgent reason to learn English. She wanted to go to the United States to tell the world about her experience as a comfort woman and force the Japanese government to apologize for trampling on human ethics.