 The title song named "어젠" ("Yesterday") was also written by Hwanhee.On 29 December 2009, Hwanhee's agency (H-Entercom) announced that Hwanhee would take a break from his first solo album's promotional activities due to an abrupt onset of health problems involving his vocal cords.After a hiatus of five months, Hwanhee released a digital duet titled "바보가슴" ("Foolish Heart") with female newcomer singer, 숙희 "Sook Hee" in May 2010.