My Husband's Girlfriend (2013)

Original title: 夫のカノジョ

Yamagishi Hoshimi, an only child, lost her father at an young age and was raised only by her mother, who works as a temporary worker at a large company. Her boss Komatsubara Mugitaro supports her a lot with her goal to become a regular employee soon. Mugitaro's wife Hishiko believes that her husband is having an affair with his subordinate Hoshimi due to his high interest in her and decides to meet her personally. At this moment, Hoshimi and Hishiko collide and happen to swap bodies. After the first confusion, they decide to continue to live the lives of each other for the moment. Mugitaro doesn't know about this strange occurrence and is more than bewildered about the completely different reactions from his "girlfriend" and his wife.