IU released a video recreating the practice room scene just before the comeback of "You and I" 15 years ago to celebrate April Fool's Day.

On the afternoon of the 1st, a video titled "[IU TV] Unreleased practice video of 'You and I' from 15 years ago (the day before the comeback)" was uploaded on the YouTube channel 'Lee Ji-geum [IU Official]'. In the video, IU recreated the makeup and styling from when she was 19 years old, showing her appearance at that time. In the video, IU acted focused on dance practice the day before the comeback, and received advice from the choreographer: "Tomorrow is the first broadcast, and if you mess this up, you'll keep messing it up for about 10 years. There's that kind of jinx, so stay sharp." To this, IU responded playfully while grabbing the choreographer's suspenders, saying, "You're the reason I keep messing up."

IU joined hands with the choreographers and said, "Let's cheer each other on for this comeback!" showing determination. One choreographer said, "If you do well, maybe in 10 years you could perform at a main stadium or something?" IU replied, "Let's not say such ridiculous things." Then she added, "I just hope that by working hard like this, someday we can perform at a gymnasium or something again." When the production team said, "We haven't even started the nationwide tour yet," IU said, "My dream is to hold a concert."

While getting her makeup done, the production team asked, "Jieun, aren't you drinking cocoa today?" IU replied, "Ah, I have to make a comeback now," fully immersing herself in the role play. When the production team mentioned her current appearance, IU responded, "I can't drink it because I have to make a comeback." IU recalled, "Back then, I used to drink cocoa like that," and when a staff member pointed out that her tone was different, she added, "Even then, I spoke lethargically. And I didn't talk much." IU recreated the atmosphere and details of the practice room from 15 years ago, reminding fans of that time.