Inspired by the conversations shared by the members and their company following the release of Cheshire, Kill My Doubt lyrically revolves around the message of overcoming adversity and self-doubt.

In October 2023, the EP was certified Million by the Korea Music Content Association (KMCA) for surpassing 1,000,000 copies sold, the group's third million-seller album.

[3] While both releases were met with commercial success,[4] "Sneakers", the lead single of Checkmate, was subject to criticism and contention, in contrast to positive reception received by the album's B-side tracks.

[5] Meanwhile, Cheshire was seen as a "mature update" to the quintet's sound, though the pre-release single "Boys Like You" was criticized by media outlets such as NME, for having "painfully juvenile" lyrics.

[13] A variety of songwriters were involved in the writing of the extended play, including Black Eyed Pilseung, who had previously worked with Twice, and Park Jin-young.

[15] The song departs from the quintet's characteristic powerful style and delves into a vulnerable approach, exploring themes of anxiety, confidence, and empowerment.

[16][17] "Cake", the second track, serves as the EP's lead single, and is characterized by the use of energetic brass and drum sounds, expressing the members' confidence.

The quintet held a showcase at the SK Olympic Handball Gymnasium in support of Kill My Doubt on the day of the EP's release.

[19] The video for "Bet on Me" aimed to capture the feeling of being alone,[34] depicting the members in everyday settings, wearing clothing contrasting with their usual bold outfits.

[39][40] In concept art released on July 11, Itzy was in a space with a "mysterious purple light" and punching bags, showcasing outfits with a "flashy sporty look".