Lead stars Ong Seong Wu and Shin Ye Eun of JTBC's new Fri-Sat drama series 'Probability' have unveiled a heart-fluttering teaser poster!

Full titled 'The Probability of Going from Friends to Lovers', the JTBC drama involves the rocky, odd relationship of Kyung Woo Yeon (Shin Ye Eun) and Lee Soo (Ong Seong Wu), a man and a woman who have been friends for 10 years. But throughout their friendship, Kyung Woo Yeon has had a running crush on Lee Soo as long as she can remember, while to Lee Soo, Kyung Woo Yeon is just a fun companion. 

You can tell just how complicated this unique relationship is just from 'Probability's latest teaser poster below, depicting Kyung Woo Yeon and Lee Soo during their past high school days as well as the present time. Also starring Dongjun, Block B's P.O, Ahn Eun Jin, and more, JTBC's 'Probability' is expected to premiere in September!