ChoA has dropped her teaser for "Thorn" for the 'Lovestruck in the City' OST.

In the music video teaser, Lee Eun Oh/Yoon Seon Ah (played by Kim Ji Won) and Park Jae Won (Ji Chang Wook) both struggle to let go of their painful past. "Thorn" is an emotional ballad featuring the vocals of ChoA, who made a comeback late last year after a long hiatus, and it's set to drop on February 12 KST.

In other news, ChoA has officially joined the cast of the lifestyle reality series 'ON/OFF'. 

Listen to ChoA's teaser above, and let us know what you think in the comments below.