One Day (2AM and 2PM song)

"One Day" is a collaborative song released in 2010 by the South Korean boy groups 2AM and 2PM, both managed by JYP Entertainment. The song was created as a theme song for the documentary film Beyond the ONEDAY ~Story of 2PM & 2AM~, which chronicled the journey and struggles of the two groups. It represented a reunion of sorts, as the members of 2AM and 2PM had originally trained together as a larger group before being split into two separate entities.

"One Day" is a ballad that emphasizes the strong bond and shared history between the members of 2AM and 2PM. The lyrics reflect themes of friendship, support, and overcoming adversity together. The song's gentle melody and heartfelt vocals aim to convey the deep connection between the two groups and their fans. The song was not promoted with active stage performances, owing to the focus on its documentary tie-in. However, it remains a significant piece in the history of both 2AM and 2PM, symbolizing their unique relationship and collective experiences.