7 years ago, an aspiring actress Suyeon came to Seoul after losing touch with her family, and is barely surviving by playing minor roles and chores in a small troupe. Then one day, Suyeon receives a call from Tongyeong and goes down there.
Thud! Thud! Thud! The noise between rooms 401 and 501 has started! Eun Soo, an aspiring writer who is no different from a jobless person, begins to observe the owner of the house upstairs, questioning the noise between the floors that tormented her while searching for a subject for a contest. Ho Kyung, the man upstairs, also began to notice the existence of Eun Soo and eventually, Eun Soo faces a shocking truth... The noise that started today "Is the story that I only imagined real?’"
Ex intelligence agent Ki-heon is tasked with safely transporting Seo Bok, the first ever human clone, who holds the secret of eternal life. Several forces try to take control of Seo Bok to serve their own agendas.
An aspiring songwriter who ekes out a living by composing music for commercials, can no longer bear the many compromises that line of work demands and decides one day that enough is enough. As he reminisces about his college years, he leaves the city for his hometown.