Kim Myungsoo was Lee Sungyeol's best friend. Lee Haena was Lee Sungyeol's best friend. so with that Myungsoo and Haena became a bestfriend. Lee Sungyeol loved Haena, she was his first love but she never knew and Sungyeol never said to her. But Haena liked Myungsoo so did He. So Haena and Myungsoo were dating. But someday, Haena pregnant and the baby was Myungsoo's but he didn't want to take the responsibility so he ran away. Lee Haea had nothing but Sungyeol.