Sandeul's new album "Thinking EP.1" is a limited-edition physical album with new songs, including songs from a thought book series previously released as a digital single.

The title track "Summer's Night" is Sandeul's self-composed song that highlights the feeling of summer nights with Sandeul's soft, warm voice. The emotional sound of waves that seem to come to mind on a summer night captivates the ears, and the relaxing guitar performance and piano beat are expected to provide calm enjoyment like the sound of waves on a summer night.