This week's broadcast of KBS2's 'Yoo Hee Yeol's Sketchbook' will be a special one, featuring a mini-concert with the sole musical guest of the day - IU!

Back on September 15, IU was spotted attending her 'Yoo Hee Yeol's Sketchbook' recording at approximately 9 AM KST. Now, insiders have given a full rundown of IU's 'Sketchbook' recording, which carried on for a total of 14-hours, until the same day at 11 PM KST.

This week's 'IU mini-concert' on 'Sketchbook' celebrates IU's 12th anniversary since debut. As a result, the singer prepared 13 unique performances of songs she hasn't performed as much in the past, starting with "BBIBBI" and moving on to "Blueming", "Eight", etc. 

According to insider reports, the mini concert 'Sketchbook' recording began early in the morning with a series of 'tech rehearsals'. Then came the 'dry rehearsals', followed by another set of 'camera rehearsals', and finally, the main recording. Throughout each of these rehearsals and main recordings, it's said that IU sang a total of 60 full-length songs. Just before 11 PM KST on this day, IU performed her closing song "Good Day" for the last time, belching out her signature 3-key note so perfectly that some staff members on site shed tears after witnessing IU's perseverance and stamina. 

Excited to see the end result of IU's 14-hour recording? Then make sure to tune in to KBS2's 'Yoo Hee Yeol's Sketchbook' this weekend on September 18, airing exactly on the date of IU's 12th debut anniversary day!