At the age of 20, three people met in the same club at a university in Seoul, Ko Tae-Young, Sa-Rang, and Dokgo I-Na. The three have been friends for 11 years in Seoul, where housing prices are high, people are crowded, and the night view is spectacular. Tae-Young, who yearned for a seemingly comfortable life, entered the design department and now works at an ordinary web design company. Sa-Rang, a nurse who has been dating her Seoul-born doctor boyfriend for over 10 years and has been living in Seoul. Dokgo I-Na, who is comfortable being alone and enjoys other people's relationships the most, became a webtoon writer. Now that they are 31, the three of them are trying new changes for a better life than now. Tae-Young, who broke up with her boyfriend, who worked at a small business for over 2 years, meets another man, and prepares to move to a large company, and Sa-Rang, who is breaking up with her boyfriend to get married. I-Na, who is trying to escape the loneliness of living and working alone. In Seoul, where it is easy to become lonely as many lives as there are, what kind of thirty-one years will they spend?

(Source: Kakaopage, translated)