Case 143

On September 6, 2022, Stray Kids uploaded a trailer to announce that they would release the seventh EP Maxident. The track listing of the EP was revealed on September 13, appearing "Case 143" as the first track and the lead single. JYP Entertainment described that the track conveys a theme the group never do before as the lead single, later confirmed that it is about love. On September 17, the mashup video, providing sneak peeks of all the EP's tracks, including "Case 143", premiered at the "Seoul Special (Unveil 11) of Maniac World Tour.

The first music video teaser for "Case 143" was uploaded on October 3, previewing the music video's worldview, while the second on the 4th depicts parts of the song and performance. The performance video was also teased on October 5. Additionally snippet and choreography were revealed via TikTok on October 6, showing the members wearing SKZoo costumes. "Case 143" was released alongside the EP and its accompanying music video on October 7.

The Japanese version of "Case 143" first appeared on December 2 on the first line-up setlist of Music Station Ultra Super Live 2022, where Stray Kids would participate on December 23. It was subsequently released on December 15 as a standalone digital single, before including on the group's debut Japanese-language studio albums The Sound, released on February 22, 2023.

"Case 143" is three minutes and twelve seconds long and was written by Stray Kids' in-house production team 3Racha, Raphael from Producing Lab, and Daviid and Yosia from 3scape. An electrohop and pop track, "Case 143" compares confused minds when falling in love with a "case" and expresses emotions through the number 143, a code for "I love you". The song was composed in the key of F♯ minor and 100 beats per minute.

Writing for Teen Vogue, Crystal Bell praised "Case 143" as "full of surprises" and described it as "a love song for someone who gets easily distracted." Bell also wrote for Paper that "This isn't some grand, romanticized love song. It's vibrant, witty, and structurally, a little odd. In other words, it's a Stray Kids song." Rhian Daly of NME described the song that is "built around an ever-changing rush of sounds, some dark and ominous, others teetering and tumbling." Idology's Squib stated that the song as "the exhilaration multiplied as the tension was further relieved from the incisive spirit that had been present since the pre-debut, which was described as "a bit of a spirited spirit."

"Case 143" experienced popularity in Japan after going viral in the video-sharing application TikTok, resulting in the song being voted first place in Best Entertainment 2022's "Best K-Pop" by Japanese website Modelpress's readers. Several other publications included in their lists of the best K-pop songs of 2022, including Dazed (36th), Teen Vogue (unranked), and SCMP's Young Post (2nd).

An accompanying music video for "Case 143" was uploaded, along with the single on October 7, 2022. Directed by 725 of SL8, the music video starts with the heart-shaped monster, utilizing CGI elements, infecting Felix, then all members, so Changbin calls the police officers, who are also Stray Kids. The police officers go to examine the crime scene and try to arrest the monsters and monster-infected Stray Kids. The first has been arrested, but the latter still falls in love. The police officers pull the big plug, and the set collapses. Then, the video is paused, and Seungmin rewinds it back. The falling-in-love Stray Kids put the plug back to stop collapsing, and they break the video as glass to leave it. The music video surpassed 100 million views on YouTube on March 28, 2023, becoming their ninth music video to reach this milestone.

The performance video was uploaded on October 15, showing the choreography scene shot at the front of car wash and the street. The Japanese version's music video premiered on January 22, 2023. It was produced by Japanese illustrator Kawaisouni!, and serves as a frame-by-frame animated remake of the original music video. Characters made by Kawaisouni!, Opanchu Usagi and Npochamu, also appeared in the music video.

Between October 7 and 23, 2022, Stray Kids promoted Maxident with "Case 143" performance at several South Korean music programs, such as Music Bank, Show! Music Core, Inkigayo, Show Champion, and M Countdown. On October 8, the group performed the song at Music Universe K-909, along with the sub-unit tracks-"3Racha", "Taste", and "Can't Stop"; and the 2022 The Fact Music Awards, alongside "Maniac". "Case 143" was added to the setlist of Maniac World Tour since Jakarta shows on November 12.

During December 2022, January 2023, the group performed "Case 143" at the 2022 Asia Artist Awards, along with "Charmer", the 2022 KBS Song Festival with "Maniac", the 2022 SBS Gayo Daejeon along with "Christmas EveL" and "24 to 25", the 2022 MBC Gayo Daejejeon alongside "Circus", and 37th Golden Disc Awards with "Super Board" and "Freeze". Stray Kids performed the Japanese version at 2022 FNS Music Festival on December 14, 2022, and six-hour special Music Station Ultra Super Live 2022 on the 23rd. In 2023, Stray Kids sang the Japanese version of the song on the YouTube channel The First Take on February 24, and performed at 74th NHK Kōhaku Uta Gassen on December 31.

Locations

• JYP Publishing (KOMCA), publishing
• Copyright Control, publishing
• Sony Music Publishing (Japan) Inc., publishing (Japanese version)
• JYPE Studios, recording, mixing
• Channie's "Room", recording
• The Mastering Palace, mastering

Personnel

• Stray Kids, vocals
  • Bang Chan (3Racha), lyrics, composition, arrangement, digital editing, recording
  • Changbin (3Racha), lyrics, composition
  • Han (3Racha), lyrics, composition
• KM-Markit, Japanese lyrics (Japanese version)
• Raphael (Producing Lab), composition, arrangement, drum, bass, synthesizer, electric guitar, computer programming
• Daviid (3scape), composition, arrangement, drum, bass, synthesizer, computer programming
• Yosia (3scape), composition, arrangement, piano, electric piano
• Lee Kyeong-won, digital editing
• Eom Se-hee, recording
• Lee Sang-yeop, recording
• Lee Tae-sub, mixing
• Dave Kutch, mastering