EXOs D.O. & Nam Ji Hyun illustrate a bittersweet love story in the period romcom series 100 Days My Prince! Known for his outstanding performances in Its Okay, Thats Love & the Along With the Gods series, D.O. (a.k.a. Do Kyung Soo) appears in his first period drama as a crown prince who loses his memory & becomes a commoner. Following Shopaholic Louis & Suspicious Partner, Nam Ji Hyun takes on her third romantic comedy as the maiden who unknowingly marries the crown prince. The mystery romcom also co-stars Yoon Tae Young ( Neighborhood Hero), Kim Jae Young ( My Secret Romance), Kang Young Seok ( Revolutionary Love), child star Heo Jung Eun ( My Fair Lady), rising actress Han So Hee ( Money Flower) & Jo Sung Ha ( Save Me).
After being attacked by assassins & falling off a cliff, crown prince Lee Yool (Do Kyung Soo) loses his memory & suddenly becomes the good-for-nothing Won Deuk. He gets taken in by a smart girl called Hong Shim (Nam Ji Hyun) who mistakes him for her fianc. The two soon marry due to a decree that Lee Yool himself had issued earlier mandating that all single people get married! As Lee Yool struggles to adjust to marriage & commoner life, the secret behind the attack also gradually comes to light. What challenges will the couple face when Won Deuk goes back to the palace & they realize their true identities?