- Title: 어쩌다 18 / Eojjeoda 18
- Also known as: 18 Again / Accidentally 18
- Genre: Fantasy, romance, comedy
- Format: Web drama / JTBC Drama Festa
- Episodes: 10 (Naver TV Cast) / 2 (JTBC)
- Broadcast network: Naver TV Cast, JTBC
- Broadcast period: 2017-Aug-28 to 2017-Sep-08 (Naver TV Cast) / 2017-Oct-08 (JTBC)
- Air time: Weekdays 07:00 (Naver TV Cast) / Sunday (2 episodes back-to-back, JTBC)
- Original soundtrack: Somehow 18 OST
A popular orthopedic surgeon, Oh Kyung Hwi, who was a loner and bullying victim in high school, goes back in time to when he was 18 years old to save his first love, who committed suicide.
- Main Cast
- Kim Bo Mi as Oh Yi Do (Kyung Hwi's older sister)
- Kim Hee Chan as Jang Seul Ki
- Yoo Joon Hong as Ma Ki Ho
- Choi Seo Hyuk (최서혁) as Baek Jin Wook
- This web drama was produced by JTBC, but was originally made available through Naver TV Cast.