Following a series of photo and video teasers, Inside Me and the lead single "I'm Cold" were simultaneously released, nearly three years after his first studio album 10 Stories.

The mini-album peaked at number seven on South Korea's national Circle Album Chart and has sold 44,000 copies since its release.

Following the completion of his mandatory military service in January 2020, Kim began actively appearing as a guest on entertainment television programs and taking part in musicals.

While developing Inside Me, he sought a sonic shift and wanted to create music which differed from the recordings of his previous albums.

He initially planned to release an album immediately after being discharged from the military, but the project was delayed due to various circumstances, including the ongoing COVID-19 pandemic in South Korea.

[4] Tamar Herman of South China Morning Post described Inside Me as a "moody" electropop and R&B record "that verges on contemporary jazz and neo soul but never quite goes where one expects".

[14] On December 1, 2020, Woollim Entertainment published a "comeback" video trailer announcing the forthcoming release of Inside Me.

[16] A 30-second "A version" album trailer was uploaded on December 6; the video displayed scenes of Kim at a bar wearing a see-through shirt.

[17] A second pair of concept photos were posted on the subsequent day; one showed Kim with tattoos on various parts of his body, and he donned a wet white shirt with disheveled hair in the other.